urinary tract imaging and pathology

146
Imaging Of The Urinary Tract DR.SULTAN ALHAJAHJEH RADIOLOGY DEPARTMENT JORDAN UNIVERSITY HOSPITAL

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Page 1: Urinary tract imaging and pathology

Imaging Of The

Urinary Tract DRSULTAN ALHAJAHJEH

RADIOLOGY DEPARTMENT

JORDAN UNIVERSITY HOSPITAL

Anatomy of the urinary tract

Pelvic calacyeal system

There are usually seven pairs of minor calyces

Minor calyx pairs combine to form two or three major calyceswhich in turn drain via their infundibula to the pelvis

The pelvis may be intrarenal or partially or entirely extrarenal

The hilum of the kidney lies medially that of the left at L1 vertebral level and that of the right slightly lower at L1L2 level owing to the bulk of the liver above

At the hilum the pelvis lies posteriorly and the renal vein anteriorly with the artery in between

Anatomy of the urinary tract

The ureters

Each is 25-30 cm long and is described as having a pelvis and

abdominal pelvic and intravesical parts

the ureter has a diameter of about 3 mm but is narrower at the

following three sites

The junction of the pelvis and ureter

The pelvic brim

The intravesical ureter where it runs through the muscular bladder

wall

Anatomy of the urinary tract

1 Right upper-pole (major) calyx

2 Right middle (major) calyx

3 Right lower-pole (major) calyx

4 Left upper-pole (major) calyx

5 Left lower-pole (major) calyx

6 Minor calyx (infundibulum of)

7 Papilla

8 Infundibulum

9 Fornix

10 Bifid left renal pelvis

11 Right renal pelvis

12 Right ureter

13 Left ureter vascular impression

14 Upper pole right kidney

15 Right psoas outline

16 Gas in body of stomach

17 Gas in transverse colon

18 Intravesical ureter

Anatomy of the urinary tract

Bladder This is a pyramidal muscular organ when empty It has a triangular-shaped base

posteriorly

The ureters enter the posterolateral angles and the urethra leaves inferiorly at the narrow neck which is surrounded by the (involuntary) internal urethral sphincter

It has one superior and two inferolateral walls which meet at an apex behind the pubic symphysiss

In the female the body of the uterus rests on its posteronotsuperior surface and the cervix and vagina are posterior with the rectum behind

In the male the neck is fused with the prostate

The bladder is supplied via the internal iliac artery via superior and inferior vesicalarteries

Urinary bladder

rectum

prostate

Anatomy of the urinary tract

The urethra The male urethra runs from the internal urethral sphincter at the neck

of the bladder to the external urethral orifice at the tip of the penis

The posterior urethra comprises the prostatic and membranous

urethra and the anterior part comprises the bulbous and penile

urethra

In females This is 4 cm long It extends from the internal urethral

sphincter at the bladder neck through the urogenital diaphragm to

the external urethral meatus anterior to the vaginal opening

1Balloon of catheter in

navicular fossa

2 Penile urethra

3 Bulbous urethra

4 Membranous urethra

5 Impression of verumontanum in

prostatic urethra

6 Filling of utricle (not usually seen)

7 Air bubbles in

contrast

Imaging techniques of the urinary

tract

kub

Ivu

Mcug

Ultrasound

Ascending urethrogram

Mri

Pelvicalyceal system

Duplex collecting system

Congenital ureteropelvic junction (UPJ) obstruction

Congenital megacalyces

(PYELO)Calyceal diverticulum

Renal papillary necrosis (RPN)

Pyonephrosis

Duplex collecting system

It is one of the most common congenital renal tract abnormalities 4-

5 It is characterised by incomplete fusion of upper and lower pole

moieties resulting in complete or incomplete duplication of the

collecting system

duplex collecting system - a duplex kidney draining into

single ureter - ie duplex kidneys duplication pelvicalcyeal systems uniting at the pelvi-ureteric junction (PUJ)

bifid ureter (ureter fissus) - two ureters that unite before emptying into

the bladder

double ureter (complete duplication) two ureters that drain separately

into the bladder or genital tract

Duplex collecting system

Orthotopic ureter drains lower pole and

enters bladder near trigone

Ectopic ureter drains upper pole and enters

bladder inferiorly and medially (Weigert-

Meyer rule) the ectopic ureter may be

stenotic and obstructed

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 2: Urinary tract imaging and pathology

Anatomy of the urinary tract

Pelvic calacyeal system

There are usually seven pairs of minor calyces

Minor calyx pairs combine to form two or three major calyceswhich in turn drain via their infundibula to the pelvis

The pelvis may be intrarenal or partially or entirely extrarenal

The hilum of the kidney lies medially that of the left at L1 vertebral level and that of the right slightly lower at L1L2 level owing to the bulk of the liver above

At the hilum the pelvis lies posteriorly and the renal vein anteriorly with the artery in between

Anatomy of the urinary tract

The ureters

Each is 25-30 cm long and is described as having a pelvis and

abdominal pelvic and intravesical parts

the ureter has a diameter of about 3 mm but is narrower at the

following three sites

The junction of the pelvis and ureter

The pelvic brim

The intravesical ureter where it runs through the muscular bladder

wall

Anatomy of the urinary tract

1 Right upper-pole (major) calyx

2 Right middle (major) calyx

3 Right lower-pole (major) calyx

4 Left upper-pole (major) calyx

5 Left lower-pole (major) calyx

6 Minor calyx (infundibulum of)

7 Papilla

8 Infundibulum

9 Fornix

10 Bifid left renal pelvis

11 Right renal pelvis

12 Right ureter

13 Left ureter vascular impression

14 Upper pole right kidney

15 Right psoas outline

16 Gas in body of stomach

17 Gas in transverse colon

18 Intravesical ureter

Anatomy of the urinary tract

Bladder This is a pyramidal muscular organ when empty It has a triangular-shaped base

posteriorly

The ureters enter the posterolateral angles and the urethra leaves inferiorly at the narrow neck which is surrounded by the (involuntary) internal urethral sphincter

It has one superior and two inferolateral walls which meet at an apex behind the pubic symphysiss

In the female the body of the uterus rests on its posteronotsuperior surface and the cervix and vagina are posterior with the rectum behind

In the male the neck is fused with the prostate

The bladder is supplied via the internal iliac artery via superior and inferior vesicalarteries

Urinary bladder

rectum

prostate

Anatomy of the urinary tract

The urethra The male urethra runs from the internal urethral sphincter at the neck

of the bladder to the external urethral orifice at the tip of the penis

The posterior urethra comprises the prostatic and membranous

urethra and the anterior part comprises the bulbous and penile

urethra

In females This is 4 cm long It extends from the internal urethral

sphincter at the bladder neck through the urogenital diaphragm to

the external urethral meatus anterior to the vaginal opening

1Balloon of catheter in

navicular fossa

2 Penile urethra

3 Bulbous urethra

4 Membranous urethra

5 Impression of verumontanum in

prostatic urethra

6 Filling of utricle (not usually seen)

7 Air bubbles in

contrast

Imaging techniques of the urinary

tract

kub

Ivu

Mcug

Ultrasound

Ascending urethrogram

Mri

Pelvicalyceal system

Duplex collecting system

Congenital ureteropelvic junction (UPJ) obstruction

Congenital megacalyces

(PYELO)Calyceal diverticulum

Renal papillary necrosis (RPN)

Pyonephrosis

Duplex collecting system

It is one of the most common congenital renal tract abnormalities 4-

5 It is characterised by incomplete fusion of upper and lower pole

moieties resulting in complete or incomplete duplication of the

collecting system

duplex collecting system - a duplex kidney draining into

single ureter - ie duplex kidneys duplication pelvicalcyeal systems uniting at the pelvi-ureteric junction (PUJ)

bifid ureter (ureter fissus) - two ureters that unite before emptying into

the bladder

double ureter (complete duplication) two ureters that drain separately

into the bladder or genital tract

Duplex collecting system

Orthotopic ureter drains lower pole and

enters bladder near trigone

Ectopic ureter drains upper pole and enters

bladder inferiorly and medially (Weigert-

Meyer rule) the ectopic ureter may be

stenotic and obstructed

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 3: Urinary tract imaging and pathology

Anatomy of the urinary tract

The ureters

Each is 25-30 cm long and is described as having a pelvis and

abdominal pelvic and intravesical parts

the ureter has a diameter of about 3 mm but is narrower at the

following three sites

The junction of the pelvis and ureter

The pelvic brim

The intravesical ureter where it runs through the muscular bladder

wall

Anatomy of the urinary tract

1 Right upper-pole (major) calyx

2 Right middle (major) calyx

3 Right lower-pole (major) calyx

4 Left upper-pole (major) calyx

5 Left lower-pole (major) calyx

6 Minor calyx (infundibulum of)

7 Papilla

8 Infundibulum

9 Fornix

10 Bifid left renal pelvis

11 Right renal pelvis

12 Right ureter

13 Left ureter vascular impression

14 Upper pole right kidney

15 Right psoas outline

16 Gas in body of stomach

17 Gas in transverse colon

18 Intravesical ureter

Anatomy of the urinary tract

Bladder This is a pyramidal muscular organ when empty It has a triangular-shaped base

posteriorly

The ureters enter the posterolateral angles and the urethra leaves inferiorly at the narrow neck which is surrounded by the (involuntary) internal urethral sphincter

It has one superior and two inferolateral walls which meet at an apex behind the pubic symphysiss

In the female the body of the uterus rests on its posteronotsuperior surface and the cervix and vagina are posterior with the rectum behind

In the male the neck is fused with the prostate

The bladder is supplied via the internal iliac artery via superior and inferior vesicalarteries

Urinary bladder

rectum

prostate

Anatomy of the urinary tract

The urethra The male urethra runs from the internal urethral sphincter at the neck

of the bladder to the external urethral orifice at the tip of the penis

The posterior urethra comprises the prostatic and membranous

urethra and the anterior part comprises the bulbous and penile

urethra

In females This is 4 cm long It extends from the internal urethral

sphincter at the bladder neck through the urogenital diaphragm to

the external urethral meatus anterior to the vaginal opening

1Balloon of catheter in

navicular fossa

2 Penile urethra

3 Bulbous urethra

4 Membranous urethra

5 Impression of verumontanum in

prostatic urethra

6 Filling of utricle (not usually seen)

7 Air bubbles in

contrast

Imaging techniques of the urinary

tract

kub

Ivu

Mcug

Ultrasound

Ascending urethrogram

Mri

Pelvicalyceal system

Duplex collecting system

Congenital ureteropelvic junction (UPJ) obstruction

Congenital megacalyces

(PYELO)Calyceal diverticulum

Renal papillary necrosis (RPN)

Pyonephrosis

Duplex collecting system

It is one of the most common congenital renal tract abnormalities 4-

5 It is characterised by incomplete fusion of upper and lower pole

moieties resulting in complete or incomplete duplication of the

collecting system

duplex collecting system - a duplex kidney draining into

single ureter - ie duplex kidneys duplication pelvicalcyeal systems uniting at the pelvi-ureteric junction (PUJ)

bifid ureter (ureter fissus) - two ureters that unite before emptying into

the bladder

double ureter (complete duplication) two ureters that drain separately

into the bladder or genital tract

Duplex collecting system

Orthotopic ureter drains lower pole and

enters bladder near trigone

Ectopic ureter drains upper pole and enters

bladder inferiorly and medially (Weigert-

Meyer rule) the ectopic ureter may be

stenotic and obstructed

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 4: Urinary tract imaging and pathology

Anatomy of the urinary tract

1 Right upper-pole (major) calyx

2 Right middle (major) calyx

3 Right lower-pole (major) calyx

4 Left upper-pole (major) calyx

5 Left lower-pole (major) calyx

6 Minor calyx (infundibulum of)

7 Papilla

8 Infundibulum

9 Fornix

10 Bifid left renal pelvis

11 Right renal pelvis

12 Right ureter

13 Left ureter vascular impression

14 Upper pole right kidney

15 Right psoas outline

16 Gas in body of stomach

17 Gas in transverse colon

18 Intravesical ureter

Anatomy of the urinary tract

Bladder This is a pyramidal muscular organ when empty It has a triangular-shaped base

posteriorly

The ureters enter the posterolateral angles and the urethra leaves inferiorly at the narrow neck which is surrounded by the (involuntary) internal urethral sphincter

It has one superior and two inferolateral walls which meet at an apex behind the pubic symphysiss

In the female the body of the uterus rests on its posteronotsuperior surface and the cervix and vagina are posterior with the rectum behind

In the male the neck is fused with the prostate

The bladder is supplied via the internal iliac artery via superior and inferior vesicalarteries

Urinary bladder

rectum

prostate

Anatomy of the urinary tract

The urethra The male urethra runs from the internal urethral sphincter at the neck

of the bladder to the external urethral orifice at the tip of the penis

The posterior urethra comprises the prostatic and membranous

urethra and the anterior part comprises the bulbous and penile

urethra

In females This is 4 cm long It extends from the internal urethral

sphincter at the bladder neck through the urogenital diaphragm to

the external urethral meatus anterior to the vaginal opening

1Balloon of catheter in

navicular fossa

2 Penile urethra

3 Bulbous urethra

4 Membranous urethra

5 Impression of verumontanum in

prostatic urethra

6 Filling of utricle (not usually seen)

7 Air bubbles in

contrast

Imaging techniques of the urinary

tract

kub

Ivu

Mcug

Ultrasound

Ascending urethrogram

Mri

Pelvicalyceal system

Duplex collecting system

Congenital ureteropelvic junction (UPJ) obstruction

Congenital megacalyces

(PYELO)Calyceal diverticulum

Renal papillary necrosis (RPN)

Pyonephrosis

Duplex collecting system

It is one of the most common congenital renal tract abnormalities 4-

5 It is characterised by incomplete fusion of upper and lower pole

moieties resulting in complete or incomplete duplication of the

collecting system

duplex collecting system - a duplex kidney draining into

single ureter - ie duplex kidneys duplication pelvicalcyeal systems uniting at the pelvi-ureteric junction (PUJ)

bifid ureter (ureter fissus) - two ureters that unite before emptying into

the bladder

double ureter (complete duplication) two ureters that drain separately

into the bladder or genital tract

Duplex collecting system

Orthotopic ureter drains lower pole and

enters bladder near trigone

Ectopic ureter drains upper pole and enters

bladder inferiorly and medially (Weigert-

Meyer rule) the ectopic ureter may be

stenotic and obstructed

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 5: Urinary tract imaging and pathology

1 Right upper-pole (major) calyx

2 Right middle (major) calyx

3 Right lower-pole (major) calyx

4 Left upper-pole (major) calyx

5 Left lower-pole (major) calyx

6 Minor calyx (infundibulum of)

7 Papilla

8 Infundibulum

9 Fornix

10 Bifid left renal pelvis

11 Right renal pelvis

12 Right ureter

13 Left ureter vascular impression

14 Upper pole right kidney

15 Right psoas outline

16 Gas in body of stomach

17 Gas in transverse colon

18 Intravesical ureter

Anatomy of the urinary tract

Bladder This is a pyramidal muscular organ when empty It has a triangular-shaped base

posteriorly

The ureters enter the posterolateral angles and the urethra leaves inferiorly at the narrow neck which is surrounded by the (involuntary) internal urethral sphincter

It has one superior and two inferolateral walls which meet at an apex behind the pubic symphysiss

In the female the body of the uterus rests on its posteronotsuperior surface and the cervix and vagina are posterior with the rectum behind

In the male the neck is fused with the prostate

The bladder is supplied via the internal iliac artery via superior and inferior vesicalarteries

Urinary bladder

rectum

prostate

Anatomy of the urinary tract

The urethra The male urethra runs from the internal urethral sphincter at the neck

of the bladder to the external urethral orifice at the tip of the penis

The posterior urethra comprises the prostatic and membranous

urethra and the anterior part comprises the bulbous and penile

urethra

In females This is 4 cm long It extends from the internal urethral

sphincter at the bladder neck through the urogenital diaphragm to

the external urethral meatus anterior to the vaginal opening

1Balloon of catheter in

navicular fossa

2 Penile urethra

3 Bulbous urethra

4 Membranous urethra

5 Impression of verumontanum in

prostatic urethra

6 Filling of utricle (not usually seen)

7 Air bubbles in

contrast

Imaging techniques of the urinary

tract

kub

Ivu

Mcug

Ultrasound

Ascending urethrogram

Mri

Pelvicalyceal system

Duplex collecting system

Congenital ureteropelvic junction (UPJ) obstruction

Congenital megacalyces

(PYELO)Calyceal diverticulum

Renal papillary necrosis (RPN)

Pyonephrosis

Duplex collecting system

It is one of the most common congenital renal tract abnormalities 4-

5 It is characterised by incomplete fusion of upper and lower pole

moieties resulting in complete or incomplete duplication of the

collecting system

duplex collecting system - a duplex kidney draining into

single ureter - ie duplex kidneys duplication pelvicalcyeal systems uniting at the pelvi-ureteric junction (PUJ)

bifid ureter (ureter fissus) - two ureters that unite before emptying into

the bladder

double ureter (complete duplication) two ureters that drain separately

into the bladder or genital tract

Duplex collecting system

Orthotopic ureter drains lower pole and

enters bladder near trigone

Ectopic ureter drains upper pole and enters

bladder inferiorly and medially (Weigert-

Meyer rule) the ectopic ureter may be

stenotic and obstructed

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 6: Urinary tract imaging and pathology

Anatomy of the urinary tract

Bladder This is a pyramidal muscular organ when empty It has a triangular-shaped base

posteriorly

The ureters enter the posterolateral angles and the urethra leaves inferiorly at the narrow neck which is surrounded by the (involuntary) internal urethral sphincter

It has one superior and two inferolateral walls which meet at an apex behind the pubic symphysiss

In the female the body of the uterus rests on its posteronotsuperior surface and the cervix and vagina are posterior with the rectum behind

In the male the neck is fused with the prostate

The bladder is supplied via the internal iliac artery via superior and inferior vesicalarteries

Urinary bladder

rectum

prostate

Anatomy of the urinary tract

The urethra The male urethra runs from the internal urethral sphincter at the neck

of the bladder to the external urethral orifice at the tip of the penis

The posterior urethra comprises the prostatic and membranous

urethra and the anterior part comprises the bulbous and penile

urethra

In females This is 4 cm long It extends from the internal urethral

sphincter at the bladder neck through the urogenital diaphragm to

the external urethral meatus anterior to the vaginal opening

1Balloon of catheter in

navicular fossa

2 Penile urethra

3 Bulbous urethra

4 Membranous urethra

5 Impression of verumontanum in

prostatic urethra

6 Filling of utricle (not usually seen)

7 Air bubbles in

contrast

Imaging techniques of the urinary

tract

kub

Ivu

Mcug

Ultrasound

Ascending urethrogram

Mri

Pelvicalyceal system

Duplex collecting system

Congenital ureteropelvic junction (UPJ) obstruction

Congenital megacalyces

(PYELO)Calyceal diverticulum

Renal papillary necrosis (RPN)

Pyonephrosis

Duplex collecting system

It is one of the most common congenital renal tract abnormalities 4-

5 It is characterised by incomplete fusion of upper and lower pole

moieties resulting in complete or incomplete duplication of the

collecting system

duplex collecting system - a duplex kidney draining into

single ureter - ie duplex kidneys duplication pelvicalcyeal systems uniting at the pelvi-ureteric junction (PUJ)

bifid ureter (ureter fissus) - two ureters that unite before emptying into

the bladder

double ureter (complete duplication) two ureters that drain separately

into the bladder or genital tract

Duplex collecting system

Orthotopic ureter drains lower pole and

enters bladder near trigone

Ectopic ureter drains upper pole and enters

bladder inferiorly and medially (Weigert-

Meyer rule) the ectopic ureter may be

stenotic and obstructed

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 7: Urinary tract imaging and pathology

Urinary bladder

rectum

prostate

Anatomy of the urinary tract

The urethra The male urethra runs from the internal urethral sphincter at the neck

of the bladder to the external urethral orifice at the tip of the penis

The posterior urethra comprises the prostatic and membranous

urethra and the anterior part comprises the bulbous and penile

urethra

In females This is 4 cm long It extends from the internal urethral

sphincter at the bladder neck through the urogenital diaphragm to

the external urethral meatus anterior to the vaginal opening

1Balloon of catheter in

navicular fossa

2 Penile urethra

3 Bulbous urethra

4 Membranous urethra

5 Impression of verumontanum in

prostatic urethra

6 Filling of utricle (not usually seen)

7 Air bubbles in

contrast

Imaging techniques of the urinary

tract

kub

Ivu

Mcug

Ultrasound

Ascending urethrogram

Mri

Pelvicalyceal system

Duplex collecting system

Congenital ureteropelvic junction (UPJ) obstruction

Congenital megacalyces

(PYELO)Calyceal diverticulum

Renal papillary necrosis (RPN)

Pyonephrosis

Duplex collecting system

It is one of the most common congenital renal tract abnormalities 4-

5 It is characterised by incomplete fusion of upper and lower pole

moieties resulting in complete or incomplete duplication of the

collecting system

duplex collecting system - a duplex kidney draining into

single ureter - ie duplex kidneys duplication pelvicalcyeal systems uniting at the pelvi-ureteric junction (PUJ)

bifid ureter (ureter fissus) - two ureters that unite before emptying into

the bladder

double ureter (complete duplication) two ureters that drain separately

into the bladder or genital tract

Duplex collecting system

Orthotopic ureter drains lower pole and

enters bladder near trigone

Ectopic ureter drains upper pole and enters

bladder inferiorly and medially (Weigert-

Meyer rule) the ectopic ureter may be

stenotic and obstructed

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 8: Urinary tract imaging and pathology

Anatomy of the urinary tract

The urethra The male urethra runs from the internal urethral sphincter at the neck

of the bladder to the external urethral orifice at the tip of the penis

The posterior urethra comprises the prostatic and membranous

urethra and the anterior part comprises the bulbous and penile

urethra

In females This is 4 cm long It extends from the internal urethral

sphincter at the bladder neck through the urogenital diaphragm to

the external urethral meatus anterior to the vaginal opening

1Balloon of catheter in

navicular fossa

2 Penile urethra

3 Bulbous urethra

4 Membranous urethra

5 Impression of verumontanum in

prostatic urethra

6 Filling of utricle (not usually seen)

7 Air bubbles in

contrast

Imaging techniques of the urinary

tract

kub

Ivu

Mcug

Ultrasound

Ascending urethrogram

Mri

Pelvicalyceal system

Duplex collecting system

Congenital ureteropelvic junction (UPJ) obstruction

Congenital megacalyces

(PYELO)Calyceal diverticulum

Renal papillary necrosis (RPN)

Pyonephrosis

Duplex collecting system

It is one of the most common congenital renal tract abnormalities 4-

5 It is characterised by incomplete fusion of upper and lower pole

moieties resulting in complete or incomplete duplication of the

collecting system

duplex collecting system - a duplex kidney draining into

single ureter - ie duplex kidneys duplication pelvicalcyeal systems uniting at the pelvi-ureteric junction (PUJ)

bifid ureter (ureter fissus) - two ureters that unite before emptying into

the bladder

double ureter (complete duplication) two ureters that drain separately

into the bladder or genital tract

Duplex collecting system

Orthotopic ureter drains lower pole and

enters bladder near trigone

Ectopic ureter drains upper pole and enters

bladder inferiorly and medially (Weigert-

Meyer rule) the ectopic ureter may be

stenotic and obstructed

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 9: Urinary tract imaging and pathology

1Balloon of catheter in

navicular fossa

2 Penile urethra

3 Bulbous urethra

4 Membranous urethra

5 Impression of verumontanum in

prostatic urethra

6 Filling of utricle (not usually seen)

7 Air bubbles in

contrast

Imaging techniques of the urinary

tract

kub

Ivu

Mcug

Ultrasound

Ascending urethrogram

Mri

Pelvicalyceal system

Duplex collecting system

Congenital ureteropelvic junction (UPJ) obstruction

Congenital megacalyces

(PYELO)Calyceal diverticulum

Renal papillary necrosis (RPN)

Pyonephrosis

Duplex collecting system

It is one of the most common congenital renal tract abnormalities 4-

5 It is characterised by incomplete fusion of upper and lower pole

moieties resulting in complete or incomplete duplication of the

collecting system

duplex collecting system - a duplex kidney draining into

single ureter - ie duplex kidneys duplication pelvicalcyeal systems uniting at the pelvi-ureteric junction (PUJ)

bifid ureter (ureter fissus) - two ureters that unite before emptying into

the bladder

double ureter (complete duplication) two ureters that drain separately

into the bladder or genital tract

Duplex collecting system

Orthotopic ureter drains lower pole and

enters bladder near trigone

Ectopic ureter drains upper pole and enters

bladder inferiorly and medially (Weigert-

Meyer rule) the ectopic ureter may be

stenotic and obstructed

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 10: Urinary tract imaging and pathology

Imaging techniques of the urinary

tract

kub

Ivu

Mcug

Ultrasound

Ascending urethrogram

Mri

Pelvicalyceal system

Duplex collecting system

Congenital ureteropelvic junction (UPJ) obstruction

Congenital megacalyces

(PYELO)Calyceal diverticulum

Renal papillary necrosis (RPN)

Pyonephrosis

Duplex collecting system

It is one of the most common congenital renal tract abnormalities 4-

5 It is characterised by incomplete fusion of upper and lower pole

moieties resulting in complete or incomplete duplication of the

collecting system

duplex collecting system - a duplex kidney draining into

single ureter - ie duplex kidneys duplication pelvicalcyeal systems uniting at the pelvi-ureteric junction (PUJ)

bifid ureter (ureter fissus) - two ureters that unite before emptying into

the bladder

double ureter (complete duplication) two ureters that drain separately

into the bladder or genital tract

Duplex collecting system

Orthotopic ureter drains lower pole and

enters bladder near trigone

Ectopic ureter drains upper pole and enters

bladder inferiorly and medially (Weigert-

Meyer rule) the ectopic ureter may be

stenotic and obstructed

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 11: Urinary tract imaging and pathology

Pelvicalyceal system

Duplex collecting system

Congenital ureteropelvic junction (UPJ) obstruction

Congenital megacalyces

(PYELO)Calyceal diverticulum

Renal papillary necrosis (RPN)

Pyonephrosis

Duplex collecting system

It is one of the most common congenital renal tract abnormalities 4-

5 It is characterised by incomplete fusion of upper and lower pole

moieties resulting in complete or incomplete duplication of the

collecting system

duplex collecting system - a duplex kidney draining into

single ureter - ie duplex kidneys duplication pelvicalcyeal systems uniting at the pelvi-ureteric junction (PUJ)

bifid ureter (ureter fissus) - two ureters that unite before emptying into

the bladder

double ureter (complete duplication) two ureters that drain separately

into the bladder or genital tract

Duplex collecting system

Orthotopic ureter drains lower pole and

enters bladder near trigone

Ectopic ureter drains upper pole and enters

bladder inferiorly and medially (Weigert-

Meyer rule) the ectopic ureter may be

stenotic and obstructed

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 12: Urinary tract imaging and pathology

Duplex collecting system

It is one of the most common congenital renal tract abnormalities 4-

5 It is characterised by incomplete fusion of upper and lower pole

moieties resulting in complete or incomplete duplication of the

collecting system

duplex collecting system - a duplex kidney draining into

single ureter - ie duplex kidneys duplication pelvicalcyeal systems uniting at the pelvi-ureteric junction (PUJ)

bifid ureter (ureter fissus) - two ureters that unite before emptying into

the bladder

double ureter (complete duplication) two ureters that drain separately

into the bladder or genital tract

Duplex collecting system

Orthotopic ureter drains lower pole and

enters bladder near trigone

Ectopic ureter drains upper pole and enters

bladder inferiorly and medially (Weigert-

Meyer rule) the ectopic ureter may be

stenotic and obstructed

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 13: Urinary tract imaging and pathology

Duplex collecting system

Orthotopic ureter drains lower pole and

enters bladder near trigone

Ectopic ureter drains upper pole and enters

bladder inferiorly and medially (Weigert-

Meyer rule) the ectopic ureter may be

stenotic and obstructed

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 14: Urinary tract imaging and pathology

Spot film taken during an IVP shows

bilateral duplex kidneys

On the left side the ureters have

fused at the level of L3 vertebra

On the right side both ureters have

opened into the bladder

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 15: Urinary tract imaging and pathology

Fluoroscopy MCU Grade 5 reflux with

double excretory system on the left side

Fusion of both ureters right before the

bladder (cystoscopy confirmed the

presence of only 2 ostia in the bladder)

Hydronephrosis

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 16: Urinary tract imaging and pathology

Drooping lily sign - a urographic

sign of duplicated renal

collecting system It refers to the

inferolateral displacement of

the opacified lower pole moiety

due to an obstructed (and

relatively unopacified) upper pole moiety

In duplicated collecting system

it is classically the upper pole

ureter that is obstructed due to

a ureterocoele and the lower

pole ureter that refluxes as

described by the Weigert-Meyer

law

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 17: Urinary tract imaging and pathology

left sided duplicated collecting system

with a distorted lower pole moiety from

obstructed upper pole This results in the

so called drooping lilly sign

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 18: Urinary tract imaging and pathology

Congenital ureteropelvic junction

(UPJ) obstruction

Most common congenital anomaly of the GU tract in neonates 20 of

obstructions are bilateral

bull Intrinsic 80 defect in circular muscle bundle

of renal pelvis

bull Extrinsic 20 renal vessels (lower pole artery

or vein)

The estimated incidence in pediatric population is at ~1 per 1000-2000

newborns and there is a recognised predilection towards the left side

(~67 of cases) and a male predominance

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 19: Urinary tract imaging and pathology

Congenital ureteropelvic junction

(UPJ) obstruction

asymptomatic or When symptomatic symptoms include recurrent urinary tract infections stone formation and even a palpable flank mass

Ultrasound

will often show a dilated renal pelvis with a collapsed proximal ureter

with Doppler sonography the obstructed kidneys can show higher RIs (resistive indices)

CT

May show evidence of hydronephrosis +- calyectasis with collapsed ureters Useful for assessing crossing vessels at the PUJ especially when surgical intervention is planned

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 20: Urinary tract imaging and pathology

Congenital ureteropelvic junction

(UPJ) obstruction Left sided

hydronephrosis is seen

with dilated and

ballooned out left renal

pelvis

Left pelviureteric

junction is markedly

narrowed with probably delayed contrast

excretion into left ureter

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 21: Urinary tract imaging and pathology

Congenital ureteropelvic junction

(UPJ) obstruction Right PUJ obstruction

Dilated renal pelvis and renal

calices with normal ureter

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 22: Urinary tract imaging and pathology

Congenital megacalyces

is an incidental finding which mimics hydronephrosis It is a result of

underdevelopment of the renal medullary pyramids with resultant

enlargement of the calyces It it more frequently seen in males

The enlarged floppy calyces predispose to stasis infection and

calculus formation There is an association with congenital

megaureter

due to the lack of normal medullary pyramids not only are the

calyces enlarged but they lack the normal imprint from the papillae

thus having a flat appearance

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 23: Urinary tract imaging and pathology

Congenital megacalyces

The renal pelvis is of normal size helping to distinguish megacalyces

from hydronephrosis

In addition to enlargement of the calyces there is often also

polycalycosis (increased number of calyces) they are crowded

and multifaceted with a mosaic-like appearance

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 24: Urinary tract imaging and pathology

Congenital megacalyces

This 10-month old male had a large right

kidney thought to be due to tumour

There are more than the usual number of

calyces

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 25: Urinary tract imaging and pathology

(PYELO)Calyceal diverticulum

Outpouching of calyx into corticomedullary region

May also arise from renal pelvis or an infundibulum

Usually asymptomatic but patients may develop calculi

bull Type I originates from minor calyx

bull Type II originates from infundibulum

bull Type III originates from renal pelvis

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 26: Urinary tract imaging and pathology

(PYELO)Calyceal diverticulum

Imaging features -

Cystic lesion connects through channel with collecting

system

bull If the neck is not obstructed diverticula opacify retrograde from the

collecting system on delayed IVP films

bull May contain calculi or milk of calcium 50

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 27: Urinary tract imaging and pathology

Calyceal diverticulum

with multiple stones a

Abdominal plain film

shows multiple calculi

(arrow) over the upper pole of the right kidney

On ten-minute excretory

urogram (EXU) all stones

are shown to be locate in

an upper pole calyceal

diverticulum (arrow)

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 28: Urinary tract imaging and pathology

(PYELO)Calyceal diverticulum

On Sonography a pyelocalyceal

diverticulum appears as a cystic lesion

which is difficult to distinguish from

simple renal cyst However the

presence of mobile echogenic and

dependent layering due to milk of

calcium is pathognomic of a

pyelocalyceal diverticulum

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 29: Urinary tract imaging and pathology

Renal papillary necrosis (RPN)

RPN represents an ischemic coagulative necrosis involving variable amounts of pyramids and medullary papillae RPN never extends to the renal cortex

Causes

Ischemic necrosis

bull Diabetes mellitus

bull Chronic obstruction calculus

bull Sickle cell disease

bull Analgesics

Necrosis due to infections

bull TB

bull Fungal

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 30: Urinary tract imaging and pathology

Renal papillary necrosis (RPN)

Imaging features

bull Enlargement (early)

bull Small collection of contrast medium extends outside the interpapillaryline in partial necrosis

bull Contrast may extend into central portion of papilla in ldquomedullary typerdquo RPN

bull Eventually contrast curves around papilla from both fornices resulting in ldquolobster-clawrdquo deformity

Sequestered sloughed papillae cause filling defects in collecting system ldquoring signrdquo

bull Tissue necrosis leads to blunted or clubbedcalyces

Multiple papillae affected in 85 Rimlike calcificationof necrotic papilla occurs

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 31: Urinary tract imaging and pathology

Renal papillary necrosis (RPN)

Classical features may appear as 4

ball on tee

forniceal excavation

lobster claw

signet ring

sloughed papilla with clubbed caly

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 32: Urinary tract imaging and pathology

Renal papillary necrosis (RPN)

Enlarged view of the left kidney showing central

papillary necrosis (top arrow) and marginal

excavation (bottom arrow) the pre-cursor to the

characteristic lobster claw appearance

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 33: Urinary tract imaging and pathology

Renal papillary necrosis (RPN)

Coronal image of the left

kidney from a CT Urogram shows numerous irregular collections of

contrast arising

from the calyces some streak-like

densities and overall distortion of

the normal medullary-calycealanatomy

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 34: Urinary tract imaging and pathology

Renal papillary necrosis (RPN)

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 35: Urinary tract imaging and pathology

Renal Papillary Necrosis Ring Sign

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 36: Urinary tract imaging and pathology

Pyonephrosis

Pyonephrosis is a term given to infection of the renal pelvic system

which can then subsequently get filled with pus and is then

complicated by obstruction

The diagnosis of pyonephrosis is suspected when the clinical

symptoms of fever and flank pain are combined with the radiologic

evidence of obstruction to the urinary tracts 1

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 37: Urinary tract imaging and pathology

Pyonephrosis

Ultrasound

Usually shows dilatation of the pelvi-calyceal system with the following additional features-

echogenic collecting system debris - considered the most reliable

sign

fluid-fluid levels within the collecting system

incomplete (dirty) echoes of collecting system gas can be

occasionally seen

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 38: Urinary tract imaging and pathology

Pyonephrosis

CT

The presence of clinical signs of infection with hydronephrosis on CT

is considered a more sensitive indicator of pyonephrosis than many

of the CT findings alone

thickening of the renal pelvic wall (gt2 mm)

parenchymal or perinephric inflammatory changes dilatation and

obstruction of the collecting system higher than usual attenuation

values of the fluid within the renal collecting system and layering of

contrast material above and anterior to the purulent fluid on

excretory studies

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 39: Urinary tract imaging and pathology

Pyonephrosis

There is a calculus noted in right

renal pelvis causing gross

hydronephrosis and parenchymal

thinning

Parenchymal thickness is less than

2 mm at places

Pelvi-calyceal system shows fluid -debris levels with few tiny calculi

No air foci are noted

Parenchymal flow is preserved

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 40: Urinary tract imaging and pathology

The Ureters

Ectopic ureter

Ureterocele

Primary megaureter

Obstruction of collecting system

Ureteral injury

Ureteral tumors

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 41: Urinary tract imaging and pathology

Ectopic ureter

Ureter does not insert in the normal location in the trigone of the bladder

Incidence MF = 16

Associations

bull 80 have complete ureteral duplication

bull 30 have a ureterocele (ldquocobra headrdquo appearanceon IVP)

Insertion Sites

bull Males ureter inserts ectopically into the bladdergt prostatic urethra gt seminal vesicles vas deferens ejaculatory ducts

bull Females ectopic ureter commonly empties into postsphinctericurethra vagina tubes perineum

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 42: Urinary tract imaging and pathology

Ectopic ureter

Intravenous urography (IVU)

It can detect abnormal ureteral insertion and associated anomalies eg renal duplication

In complete duplex kidney and ureter the ectopic ureter usually drains the upper moiety and associated with ureterocele and obstruction

Voiding cystourethrogram

Usually the ectopic ureter is associated with vesico-ureteric reflux which can detected and graded with VCUG

Ultrasound

Associations and complications such as duplex kidneys hydronephrosis andureterocoele can be also be assessed

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 43: Urinary tract imaging and pathology

Ectopic ureter

A child with urinary incontinence

and recurrent urinary tract infection

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 44: Urinary tract imaging and pathology

Ectopic ureter

An ectopic ureter is identified and

inserted into the posterior urethra

Associated grade III vesico-ureteric

reflux is also noted

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 45: Urinary tract imaging and pathology

Ureterocele

A ureterocele refers to a herniation of the distal ureter into the bladder Two types

Simple (normal location of ureter) 25

bull Almost always occurs in adults

bull Usually also symptomatic in children

Ectopic (abnormal location of ureter) 75

bull Almost always associated with duplication

bull Unilateral 80

bull May obstruct entire urinary tract because of prolapse into the bladder neck causing bladder outlet obstruction

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 46: Urinary tract imaging and pathology

Ureterocele

Radiographic Features

bull Ureterocele causes filling defect in bladder on IVP

bull Typical appearance of a cystic structure by US

bull Ureterocele may be distended collapsed or everted to represent a

diverticulum

Complications

Ureteroceles may contain calculi

May be very large (bladder outlet obstruction)

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 47: Urinary tract imaging and pathology

Ureterocele

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 48: Urinary tract imaging and pathology

Megaureter

Congenital megaureter is a basket-term to encompass causes of an

enlarged ureter which are intrinsic to the ureter rather than as a result

of a more distal abnormality eg bladder urethra It encompasses

obstructed primary megaureter

refluxing primary megaureter (although vesico-ureteric reflux (VUR) is

a cause of primary congenital megaureter it is usually considered

separately)

non-refluxing unobstructed primary megaureter

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 49: Urinary tract imaging and pathology

Obstructive primary megaureter

Obstructive primary megaureter is related to a distal adynamic

segment with proximal dilatation and is a common cause of

obstructive uropathy in children It is analogous to oesophageal

achalasia or colonic Hirschsprung disease although lack of ganglion cells within the wall of the ureter has not been proven to be the

cause

the ureter tapers to a short segment of normal caliber or narrowed

distal ureter usually just above the vesicoureteric junction (VUJ)

The distal ureter above this narrowed segment is most dilated (similar

to achalasia)

There is associated hydronephrosis and active peristaltic waves can

be seen on ultrasound

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 50: Urinary tract imaging and pathology

Refluxing primary megaureter

Refluxing primary megaureter is a result of an

abnormal vesico-ureteric junction which

impedes the normal anti-reflux mechanisms This

can be due to a short vertical intramural

segment congenital paraureteric diverticulum

ureterocoele with or without associated

duplicated collecting system etc

vesicoureteric reflux is demonstrated

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 51: Urinary tract imaging and pathology

Non-refluxing unobstructed primary

megaureter

This is thought to be the most common cause of primary megaureter

in neonates and even though the vesicoureteric junction is normal

with no evidence of reflux or obstruction the ureter is enlarged The

cause for this is unknown

there is absent or only a minor degree of hydronephrosis Although

rare congenital megaureter may co-exist with congenital

megacalyces 1 making assessment of hydronephrosis more difficult

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 52: Urinary tract imaging and pathology

Dilation and

elongation of both

ureters left gtgt right

Small left kidney

with pyelonephritic

scarring and

sloughed necrotic

papillae Single

pyelonephritic scar

on the right

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 53: Urinary tract imaging and pathology

Primary megaureter - ldquoA 10 month child came

for the workup of recurrent UTI

Primary megaureter is diagnosed in the

absence of reflux stricture calculus or

ureterocelerdquo

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 54: Urinary tract imaging and pathology

Vesicoureteral reflux (VUR)

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine

from the bladder into the upper urinary tract and is typically a

problem encountered in young children

The incidence of UTI is 8 in females and 2 in males

Reflux from the bladder into the upper urinary tract predisposes to

pyelonephritis by allowing entry of bacteria to the usually sterile

upper tract

As such the diagnosis is first suspected after a urinary tract infection

in a young child

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 55: Urinary tract imaging and pathology

Vesicoureteral reflux (VUR)

Vesicoureteric reflux is in the majority of cases the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunne

MCUG

The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG)

presence and grade of VUR

whether reflux occurs during micturition or during bladder filling

presence of associated anatomical anomalies

ultrasound

Routine ultrasound is usually also performed (in addition to VCUG) to assess the renal parenchyma for evidence of scarring or anatomic anomalies

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 56: Urinary tract imaging and pathology

Vesicoureteral reflux (VUR)

bull Grade I reflux to ureter but not to kidney

bull Grade II reflux into ureter pelvis and

calyces without dilatations

bull Grade III reflux to calyces with mild

dilatationblunted fornices

bull Grade IV to calyces with moderate

dilatationobliteration of fornices

bull Grade V gross dilatation tortuous ureters

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 57: Urinary tract imaging and pathology

Vesicoureteral reflux (VUR)

Voiding cystourethrogram demonstrates

reflux into both kidneys with dilatation of

the ureters and renal collecting system The

calyxes are distended and blunted The

urethra appears normal

This case illustrates typical bilateral grade V

vesicoureteric reflux

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 58: Urinary tract imaging and pathology

Vesicoureteral reflux (VUR)

VCUG demonstrating

bilateral Grade III

vesicoureteral reflux

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 59: Urinary tract imaging and pathology

Vesicoureteral reflux (VUR)

Pre-void contrast filled bladder

demonstrated bilateral vesico-

ureteral reflux with mildly tortuous

and moderately dilated ureters

with contrast reaching blunted

dilated calyces Findings are

keeping with bilateral type 4

vesico-ureteral reflux

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 60: Urinary tract imaging and pathology

Obstruction of collecting

system

Causes

bull Calculi

bull Tumor

bull Previous surgery (ligation edema clot)

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 61: Urinary tract imaging and pathology

Urolithiasis

refers to the presence of calculi anywhere along the course of the urinary tracts

The lifetime incidence of renal stones is high seen in as many as 5 of women and 12 of males

By far the most common stone is calcium oxalate however the exact distribution of stones depends on the population and associated metabolic abnormalities

calcium oxalate +- calcium phosphate ~75

struvite (triple phosphate) 15

pure calcium phosphate 5-7

uric acid 5-8

cystine 1

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 62: Urinary tract imaging and pathology

Plain film

Calcium containing stones are radiopaque

calcium oxalate +- calcium phosphate

struvite (triple phosphate) - usually opaque but variable

pure calcium phosphate

Lucent stones include

uric acid

cystine

Indinavir stones

pure matrix stones

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 63: Urinary tract imaging and pathology

Ct

On CT almost all stones are opaque but vary considerably in density

calcium oxalate +- calcium phosphate 400-600HU

struvite (triple phosphate) usually opaque but variable

pure calcium phosphate 400-600HU

uric acid 100-200HU

cystine opaque

Two radiolucent stones are worth mentioning 11

Indinavir stones - (anti-retroviral drug) radiolucent and usually undetectable on CT 5

pure matrix stones

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 64: Urinary tract imaging and pathology

Ct

In patients with little retroperitoneal fat distinguishing a ureteric calculus from a phlebolith can be challenging Two signs have been found helpful 12

comet-tail sign - favours a phlebolith

soft-tissue rim sign - favours a ureteric calculus

comet-tail sign The sign refers to a tail of soft tissue extending from a calcification representing the collapsedscarredthrombosed parent vein When well seen it is said to have a positive predictive value of 100 1

The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall Phleboliths on the other hand usually have imperceptible walls (although up to 8 may have a soft tissue rim sign 2) but may have a comet-tail sign

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 65: Urinary tract imaging and pathology

Ct

Findings of ureteral obstruction include

( 1 ) mild dilatation of the pelvicalyceal system and ureter (3 mm)

proximal to the stone

( 2 ) slight decrease in attenuation of the affected kidney caused by

edema

( 3 ) perinephric soft tissue stranding representing edema in the

perinephric and periureteral fat

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 66: Urinary tract imaging and pathology

Nonenhanced CT image shows an

obstructing left proximal ureteral

calculus with a slight soft-tissue rim

around the stone (ie rim sign)

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 67: Urinary tract imaging and pathology

40 Male patient complaining

of right renal colic with

hematuria

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 68: Urinary tract imaging and pathology

An oval shaped radiodense

stone is seen at the junction

between upper 23 and lower

13 of the right ureter measuring

about 05 x 1 cm along its

maximum diameters and eliciting

density of about (690 HU)

associated with marked dilatation of the right pelvi-

calyceal system and proximal

part of the right ureter

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 69: Urinary tract imaging and pathology

IVP (30-minute delay image) of the right kidney shows a moderately hydronephrotic collecting system to the

level of a proximal ureteral stone (arrow) Source emedicine

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 70: Urinary tract imaging and pathology

13 minutes after infusion of contrast

medium there is contrast of the right

pyelon and in the bladder but yet no

contrast of the left pyelon There is

also contrast outlining the left kidney

whereas it has already cleared from

the right (delayed nephrogram)

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 71: Urinary tract imaging and pathology

Two hours after infusion you can appreciate a

distension of the left ureter and a

hydronephrosis of the left pyelon

This examination demonstrates the typical IVP

features of collecting system dilatation and a

delayed nephrogram secondary to a distal

obstructing calculus In this case the calculus is

well seen radiographically

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 72: Urinary tract imaging and pathology

30 year old male right flank

pain ultrasound shows proximal

hydroureter and mild

hydronephrosis

Scout- apparently normal with

no evidence of calculus

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 73: Urinary tract imaging and pathology

10 min film- right sided proximal

hydroureter and mild dilatation of

pelvicalyceal system

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 74: Urinary tract imaging and pathology

15 min film- findings are persistent and

a filling defect is noted at the L3-L4

level

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 75: Urinary tract imaging and pathology

Ultrasound

Ultrasound is frequently the first investigation of the renal tract and

although by no means as sensitive as CT it is often able to identify

calculi Small stones and those close to the corticomedullary

junction can be difficult to reliably identify Ultrasound compared to CT-KUB reference showed a sensitivity of only 24 in identifying

calculi Nearly three-quarters of calculi not visualised were 3mm or

less in size13 Features include 7

echogenic foci

acoustic shadowing

twinkle artefact on color Doppler

color comet-tail artefact 9

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 76: Urinary tract imaging and pathology

80 year old female Non

specific flank pain

Limited history due

patients confusion

Right hydronephrosis

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 77: Urinary tract imaging and pathology

Left ureteric jet present (ie

left ureter non obstructed)

No ureteric jet on the right

(suspicious although not in itself diagnostic for ureteric

obstruction)

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 78: Urinary tract imaging and pathology

Shadowing calculus at the

right VUJ

Comet tail artefact supports

the presence of a calculus

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 79: Urinary tract imaging and pathology

Ureteral tumors

Types

Benign tumors

bull Epithelial inverted papilloma polyp adenoma

bull Mesodermal fibroma hemangioma myoma lymphangioma

bull Fibroepithelial polyp mobile long intraluminal mass ureteral intussusception

Malignant tumors

bull Epithelial transitional cell carcinoma SCC

adenocarcinoma

bull Mesodermal sarcoma angiosarcoma

carcinosarcoma

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 80: Urinary tract imaging and pathology

Ureteral tumors

Due to the small caliber of the ureter tumours are more likely to

obstruct the kidney at small tumour size

Obstruction may lead to hyrdonephrosis with or without hydroureter

and may also result in a non-functioning kidney or delayed

nephrogram

bull Bergmans coiled catheter sign on retrograde pyelogram the

catheter is typically coiled in dilated portion of ureter just distal to the

lesion

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 81: Urinary tract imaging and pathology

Ureteral tumors

Smaller or polypoid tumours may be seen as filling

defects and if they cause partial long-standing

obstruction may result in focal dilatation of the

ureter at the site of the tumour This may lead to

the so-called goblet sign best seen on

retrograde ureterography 2

Occasionally circumferential thickening of the ureteric wall results from diffuse infiltration an may

have an apple core appearance 4

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 82: Urinary tract imaging and pathology

Ureteral tumors

Prognosis

bull 50 of patients will develop bladder cancer

bull 75 of tumors are unilateral

bull 5 of patients with bladder cancer will develop ureteral cancer

Sites of metastatic spread of primary ureteral neoplasm

bull Retroperitoneal lymph nodes 75

bull Liver 60

bull Lung 60

bull Bone 40

bull Gastrointestinal tract 20

bull Peritoneum 20

bull Other (lt15) adrenal glands ovary uterus

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 83: Urinary tract imaging and pathology

Ureteral tumors

CT demonstrates a very large

right sided ureteric mass with

trapped contrast which almost

mimics a vascular aneurysm and

proximal long

standing hydronephrosis

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 84: Urinary tract imaging and pathology

Ureteric injury

Ureteric injury is a relatively uncommon but serious event which may result in serious complications as diagnosis is often delayed

Ureteric injuries unreliably demonstrate macro- or micro-scopichaematuria as it may be absent in up to 25 of patients

There is a wide-range of injury

injury to the mucosa of the ureter post lithotripsy

perforation and false passage

partial or complete ureteric transection

complete ureteric avulsion

loss of ureteric segment

ligation

dissection

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 85: Urinary tract imaging and pathology

Ureteric injury

Iatrogenic(most commonly injured after gynaecological procedures)

Traumatic

Classification

Ureteric injury can be classified into three types according to its site

upper-third

upper-third and pelvico-ureteric junction (PUJ) most affected by blunt trauma 5 7

mid-third

distal-third

most common site

often following iatrogenic injury

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 86: Urinary tract imaging and pathology

Ureteric injury

Fluoroscopy

Excretory intravenous urography if CT is not available demonstrates

contrast leakage and spillage outside the course of the urinary

system

Retrograde pyelography may be performed if both

excretory intravenous urographyand CT with intravenous

contrast are inconclusive and there is still a high suspicion of injury 1

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 87: Urinary tract imaging and pathology

Ureteric injury

CT

CT with intravenous contrast and delayed scan with full reformatted

sagittal and coronal images and 3D reconstruction The delayed

scan should be performed between 5-8 minutes after IV contrast to

ensure a CT-IVU (aka excretory phase) set of images is acquired

intra-abdominal fluid collections without other cause shown

contrast extravasation from renal hilumPUJ (usually medially)

without associated renal injury

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 88: Urinary tract imaging and pathology

Ureteric injury

Post emergency caesarean section

intraperitoneal tube drainage high

output

Contrast leakage and spillage is seen in

the left side of pelvis in the region of lower

third left ureter denoting a left ureteric

injury

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 89: Urinary tract imaging and pathology

Bladder

Bladder exstrophy

Bladder diverticulum

Bacterial cystitis

Emphysematous cystitis

Neurogenic bladder

Bladder calculi

Malignant bladder neoplasm

Bladder injuries

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 90: Urinary tract imaging and pathology

Bladder exstrophy

Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect The severity of these defects is widely variable

The estimated incidence of bladder exstrophy is 110000-50000 live births

It is thought to be caused by a developmental defect of the cloacal membrane which results in a subsequent eversion of the bladder mucosa This then protrudes out like the mass like lesion

General associations

extension of the bladder defect into the urethra

cryptorchidism

bilateral inguinal herniation

OEIS complex

epispadia

vaginal duplication

clitoral cleft

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 91: Urinary tract imaging and pathology

Bladder exstrophy

Imaging findings include a soft-tissue mass extending from a large

infra-umbilical anterior wall defect which may be close to the

umbilical arterial exits

The absence of a normal urinary bladder and a low-lying umbilical

cord insertion may also indicate the diagnosis

Failure of the pubic bones to meet in the midline (widened pubic

symphysis) This appearance on AP plain radiograph of the pelvis

has been likened to a manta ray swimming towards you (manta ray

sign)

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 92: Urinary tract imaging and pathology

Bladder exstrophy

Marked widening of the pubic

symphysis (manta ray

appearance) consistent with

bladder exstrophy for which the

patient had a known history

In terms of a cause for hip pain

there is no fracture identified but

there is mild left hip degenerative disease and mild

bilateral greater tuberosity

irregularity suggesting chronic

gluteal tendinosis

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 93: Urinary tract imaging and pathology

Bladder exstrophy

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 94: Urinary tract imaging and pathology

Bladder diverticulum

Bladder diverticulum are outpouchings from the bladder wall

whereby mucosa herniates through the bladder wall

They may be solitary or multiple in nature and can very considerably

in size

Diverticulae may be congenital or acquired A range of causes of

urinary bladder diverticula are described

Acquired diverticula are more common usually occurring the

context of a trabeculated bladder resulting from chronic bladder outlet obstruction

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 95: Urinary tract imaging and pathology

Bladder diverticulum

Diverticula are often an incidental finding on imaging investigations

including ultrasound CT MRI and IVU

They may be associated with a range of complications including

infection

reflux

stone formation

malignancy

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 96: Urinary tract imaging and pathology

Bladder diverticulum

IVU images shows a diverticulum

at the right lateral wall

Note the elevated base of the

bladder due to the enlarged

prostate

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 97: Urinary tract imaging and pathology

Bladder diverticulum

Congenital diverticulae are

solitary and are most often

discovered during childhood

Acquired bladder diverticulae

are the result obstruction of the

bladder outlet or bladder

dysfunction They are often

multiple and typically seen in older men

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 98: Urinary tract imaging and pathology

Bacterial cystitis

Acute Cystitis

Pathogens E coli gt Staphylococcus gt Streptococcus

gt Pseudomonas

Predisposing Factors

bull Instrumentation trauma

bull Bladder outlet obstruction neurogenic bladder

bull Calculus

bull Cystitis

bull Tumor

Imaging Features

bull Mucosal thickening (cobblestone appearance)

bull Reduced bladder capacity

bull Stranding of perivesical fat

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 99: Urinary tract imaging and pathology

Emphysematous cystitis

Emphysematous cystitis refers to gas forming infection of the bladder wall

Risk factors include

female sex reported MF ratio 12

immunocompromised state

diabetes mellitus may be present in ~50 of cases 2

neurogenic bladder

transplant recipients

The most common causative organism is E coli with other organisms including Enterobacter aerogenes Klebsiellapneumonia Proteus mirabilis Staphylococcus aureus

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 100: Urinary tract imaging and pathology

Emphysematous cystitis

CT

CT is a highly sensitive examination that allows early detection of

intraluminal or intramural gas

CT is also useful in evaluating other causes of intraluminal gas such

as enteric fistula formation from adjacent bowel carcinoma or

inflammatory disease

Ultrasound

Can demonstrate echogenic air within the bladder wall with dirty

shadowing artefact

Ultrasound will also commonly demonstrate diffuse bladder wall

thickening and increased echogenicity

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 101: Urinary tract imaging and pathology

Emphysematous cystitis

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 102: Urinary tract imaging and pathology

Neurogenic bladder

Term applied to a dysfunctional urinary bladder that results from an

injury to the central or peripheral nerves that control and regulate

urination

Injury to the brain brainstem spinal cord or peripheral nerves from

various causes including infection trauma malignancy or vascular

insult can result in a dysfunctional bladder 3

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 103: Urinary tract imaging and pathology

Neurogenic bladder

In a large cohort study the mean age of neurogenic bladder

patients was 625 years and resultant etiologies included 4

multiple sclerosis ~17

Parkinson disease ~15

cauda equina syndrome ~9

paralytic syndrome ~8

stroke complications ~6

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 104: Urinary tract imaging and pathology

Neurogenic bladder

A number of classification schemes exist for neurogenic bladders

including the Lapides classification which remains popular

sensory neurogenic bladder posterior columns of the spinal cord or

afferent tracts leading from the bladder

motor paralytic bladder damage to motor neurons of the bladder

uninhibited neurogenic bladder incomplete spinal cord lesions

above S2 or cerebral cortex or cerebropontine axis lesions

reflex neurogenic bladder complete spinal cord lesions above S2 -

may lead to pine cone bladder

autonomous neurogenic bladder conus or cauda equina lesions

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 105: Urinary tract imaging and pathology

Neurogenic bladder

uoroscopicIVP

Sensory neurogenic bladder

Inability to sense bladder fullness results in a large rounded and smooth bladder Voiding is often preserved

Motor paralytic bladder

Atonic large bladder with inability of detrusor contraction during voiding

Unhibited neurogenic bladder

Rounded bladder with a trabeculated apperance to the mucosa above the trigone from detrusor contractions On voiding large interureteric ridge is noted

Reflex neurogenic bladder

Results from detrusor hyperreflexia with a dyssynergic sphincter This leads to contrast extension to the posterior urethra and an elongated pointed urthera with pseudodverticula

Autonomous neurogenic bladder

Intermediate between detrusor hyperreflexia (contracted) and dysreflexia (atonic)

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 106: Urinary tract imaging and pathology

Neurogenic bladder

Ultrasound

Detailed images of the bladder often demonstrate a thick wall with

a small contracted or large atonic bladder

A large post void residual is often noted

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 107: Urinary tract imaging and pathology

Neurogenic bladder

VCUR examination

demonstrate elongated

distended urinary bladder with

multiple urinary bladder

diverticulae characteristic of

neurogenic bladder

Grade III VUR on the left side is

also demonstrated

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 108: Urinary tract imaging and pathology

Neurogenic bladder Neurogenic bladder typically occurs in

those with sacral abnormalities at birth

The appearances has been described as

a Christmas tree of pine cone bladder

The shape of the bladder is highly

abnormality with an elongated appearance with the dome like the top of

a Christmas tree

The associated bladder wall hypertrophy

gives an outline which mimics the

decorations that adorn a Christmas tree

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 109: Urinary tract imaging and pathology

Neurogenic bladder

A pine cone bladder or christmas tree bladder is a cystogram appearance in which the bladder is elongated and pointed with thickened trabeculatedwall

It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesions (above S2-S4) or epiconal lesions (in and around S2-S4)

It is however not pathognomonic of a neurogenic bladder and can be seen in patients with lesions anywhere along the sacral reflex arc leading to poor detrusor compliance Occasionally it is also seen in bladder neck obstruction of a non-neurogenic cause

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 110: Urinary tract imaging and pathology

Bladder calculi

Bladder calculi occur either from migrated renal calculi or urinary

stasis

Bladder calculi can be divided into primary and secondary stones

primary stones form de novo in the bladder

secondary stones are either from renal calculi which have migrated

down into the bladder or from concretions on foreign material (eg

urinary catheters)

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 111: Urinary tract imaging and pathology

Bladder calculi

associated with -

bladder outlet obstruction

cystocoele

neurogenic bladder

foreign body

Radiographic features

Plain Film

Usually densely radio-opaque calculi may be single or multiple and often large Frequently lamination is observed internally like the skin of an onion

Ultrasound

Sonographically they are mobile echogenic and shadow distally

They may be associated with bladder wall thickening due to inflammation

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 112: Urinary tract imaging and pathology

Bladder calculi

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 113: Urinary tract imaging and pathology

Malignant bladder neoplasmClinical Finding

bull Painless hematuria

Types and Underlying Causes

Transitional cell carcinoma 90

bull Aniline dyes

bull Phenacetin

bull Pelvic radiation

bull Tobacco

bull Interstitial nephritis

SCC 5

bull Calculi

bull Chronic infection leukoplakia

bull Schistosomiasis

Adenocarcinoma 2

bull Bladder exstrophy

bull Urachal remnant

bull Cystitis glandularis 10 pass mucus

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 114: Urinary tract imaging and pathology

Malignant bladder neoplasm

Ct

bladder transitional cell carcinomas appear as either focal regions of thickening of the bladder wall or as masses protruding into the bladder lumen or in advanced cases extending into adjacent tissues

The masses are of soft tissue attenuation and may be encrusted with small calcifications

MRI

MRI is superior to other modalities in locally staging the tumour and is in some instances able to distinguish T1 from T2 tumours on T2 weighted image

T1 isointense compared to muscle 4

T2 slightly hyperintense compared to muscle

T1 C+ (Gd) shows enhancement

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 115: Urinary tract imaging and pathology

Polypoidal enhancing filling

defect arising from the left

bladder wall is typical of

transitional cell cancer No

obstruction to the left ureteric

orifice nor invasion through the

bladder wall

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 116: Urinary tract imaging and pathology

Malignant bladder neoplasm

Mural broad-based lesion lining the left aspect of

Bladder The lesion shows

internal flow on Doppler

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 117: Urinary tract imaging and pathology

Malignant bladder neoplasm

Polypoidal irregular mural thickening of the left lateral and posterior wall of the urinary bladder which coalesce to form large fungating mass arising from left lateral wall are seen and extends through the wall to invade the perivesical fat

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 118: Urinary tract imaging and pathology

Bladder injuries

Extraperitoneal bladder rupture

Extraperitoneal rupture is the most common type of bladder injury accounting for ~85 (range 80-90) of cases

It is usually the result of pelvic fractures or penetrating trauma

Cystography reveals a variable path of extravasated contrast material

Intraperitoneal bladder rupture

Occurs in approximately ~15 (range 10-20) of major bladder injuries and typically is the result of a direct blow to the already distended bladder

Cystography demonstrates intraperitoneal contrast material around bowel loops between mesenteric folds and in the paracolic gutters

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 119: Urinary tract imaging and pathology

Bladder injuries

Classification of Bladder Injury

bull Type 1 Bladder contusion

bull Type 2 Intraperitoneal rupture

bull Type 3 Interstitial bladder injury

bull Type 4 Extraperitoneal rupture

bull Type 4a Simple extraperitoneal rupture

bull Type 4b Complex extraperitoneal rupture

bull Type 5 Combined bladder injury

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 120: Urinary tract imaging and pathology

Bladder injuries

CT

Bladder rupture is one form of genitourinary tract trauma along with

renal trauma and urethral injuries

Contrast enhanced CT is the imaging technique of choice for

bladder injuries in the form of CT cystography

This may be combined with standard CT to evauluate the upper

tracts

Standard cystography has a more limited role

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 121: Urinary tract imaging and pathology

Bladder injuries

Bladder catheter balloon in the intraperitoneal space

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 122: Urinary tract imaging and pathology

Bladder injuries

Postvoid film shows a flame-

shaped density adjacent to lateral

walls of bladder representing

extra-peritoneal contrast from a

bladder rupture

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 123: Urinary tract imaging and pathology

The Urethra

Posterior urethral valves (PUVs)

Urethral injuries

Urethral strictures

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 124: Urinary tract imaging and pathology

Posterior urethral valves (PUVs)

Posterior urethral valves (PUVs) are the most common congenital

obstructive lesion of the urethra and a common cause of

obstructive uropathy in infancy

Posterior urethral valves are congenital and only seen in male

infants 2 The estimated incidence is at ~1 in 10000-25000 live births

with a higher rate of incidence in utero

Clinical presentation depends on the severity of obstruction In

severe obstruction the diagnosis is usually made antenatally

The fetus will be small for gestational age and ultrasound

examination will demonstrate oligohydramnios

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 125: Urinary tract imaging and pathology

Posterior urethral valves (PUVs)

Associations

Posterior urethral valves are also seen in association with other

congenital abnormalities including

chromosomal abnormalities eg Down syndrome 5

bowel atresia

craniospinal defects

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 126: Urinary tract imaging and pathology

Posterior urethral valves (PUVs)

UltrasoundAntenatal ultrasound

On antenatal ultrasound the appearance is that of marked distention and hypertrophy of the bladder with or without hydronephrosis and hydroureter and depending on the severity oligohydramnios and renal dysplasia

Postnatal ultrasound

The bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)

The kidneys in most cases are hydronephrotic although it is important to note that in up to 10 of cases they appear normal 5 They may also be hyperechoic with loss of the normal corticomedullary differentiation a manifestation of renal dysplasia 5

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 127: Urinary tract imaging and pathology

Posterior urethral valves (PUVs)

Voiding cystourethrogram

Voiding cystourethrogram (VCUG) is the best imaging technique for the diagnosis of posterior urethral valves

The diagnosis is best made during the micturition phase in a lateral or oblique views such that the posterior urethra can be imaged adequately

Findings include

dilatation and elongation of the posterior urethra (equivalent of the ultrasonographic keyhole sign)

linear radiolucent band corresponding to the valve (only occasionally seen)

vesicoureteral reflux (VUR) seen in 50 of patients

bladder trabeculationdiverticula

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 128: Urinary tract imaging and pathology

Posterior urethral valves (PUVs)

Keyhole sign Rotated image of an

antenatal ultrasound of the foetal

pelvis demonstrating the keyhole

sign created by the distend

bladder and posterior urethra

The keyhole sign is an

ultrasonograhic sign seen in boys

with posterior urethral valves It

refers to the appearance of

posterior urethra which is dilated

and associated thick walled

distended bladder which on

ultrasound may resemble a key

hole

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 129: Urinary tract imaging and pathology

Posterior urethral valves (PUVs)

Micturating

cystourethrogram reveals

marked dilatation of the

prostatic portion of the

urethra consistent with

posterior urethral valves

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 130: Urinary tract imaging and pathology

Posterior urethral valves (PUVs)

Ultrasound reveals marked bilateral hydronephrosis

and hydroureter There is dependent echogenic

debris seen throughout the renal collecting system

consistent with infection

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 131: Urinary tract imaging and pathology

Urethral injuries

Urethral injuries can result in long-term morbidity and most

commonly result from trauma

The male urethra is much more commonly injured than the female

urethra

Clinically blood of the external urethral meatus or vaginal introitus

may be seen but is an unreliable sign

Male urethral injuries are divided into anterior (penilebulbar) and

posterior (membranousprostatic) urethral injuries

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 132: Urinary tract imaging and pathology

Urethral injuries

Classification

blunt trauma due to shearing or straddle injuries associated with

pelvic fractures (occurs in ~10) often associated with bladder

injury

penetrating trauma eg stab wounds gunshot wounds dog bites

(more commonly affect the anterior urethra)

iatrogenic for example urethral instrumentation eg

catheterisation Foley catheter removal without balloon deflation

cystoscopypost-surgical (eg surgery for benign prostatic

hyperplasia)

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 133: Urinary tract imaging and pathology

Urethral injuries

Fluoroscopy

Retrograde urethrography is the modality of choice

It will demonstrate extraluminal contrast which has extravasated from the urethra

CT

CT cystography can be performed but this is much less specific for urethral vs bladder injury

Other features of urethral injury include retropubic and perivesicalhaematoma and obscuration of the urogenital fat plane

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 134: Urinary tract imaging and pathology

Urethral injuries

Retrograde urethrogram in

a patient with pelvic

fractures demonstrates

contained contrast leakage

at the posterior urethra

(membranous portion)

Contrast does ascend into

the bladder and therefore the urethral injury is

incomplete

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 135: Urinary tract imaging and pathology

Urethral injuries

there is a small amount of

extravasated contrast (from

prior urethrogram) within the

retro-pubic space (cave of

Retzius) inferior

extraperitoneal pelvic cavity

and tracking into the

perineumperineal muscles and adductor musculature of

the left thigh

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 136: Urinary tract imaging and pathology

Urethral stricture

Clinical presentation

poor urine stream

Aetiology

Infection(gonococcal urethritis (more common))

trauma

straddle injury (most common)

pelvic fractures

iatrogenic

instrumentation

prolonged catheterisation

transurethral resection of the prostate

open radical prostatectomy

urethra reconstruction (hypospadiaepispadia)

congenital

uncommon

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 137: Urinary tract imaging and pathology

Urethral stricture

Past history of

chlamyida infection

20mm stricture in the

bulbous urethra

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 138: Urinary tract imaging and pathology

Urethral stricture

Short segment (5mm) stricture at

the junction of the penile and

bulbous urethra

Filling defect related to

lubricant jelly used

Thank You

Page 139: Urinary tract imaging and pathology

Thank You