RENAL TRAUMA

Injury to the kidney is seen in approximately 8%–10% of patients with blunt or

penetrating abdominal injuries The vast majority (80%–90%) of cases involve

blunt rather than penetrating injury.

Active bleeding

•The CT appearance

of intraperitoneal

blood depends on the

age and physical

state of the clot.

• IMMEDIATELY AFTER

HEMORRHAGE, INTRAPERITONEAL

BLOOD HAS THE SAME

ATTENUATION AS CIRCULATING

BLOOD OF 20-30 HU

Renal arteries

Renal veins

• Relation to other layers

• The renal fascia relates to the other layers in the following manner (moving from innermost to outermost) :

• renal cortex

• renal capsule

• perinephric fat ( or "perirenal fat

• renal fascia

• paranephric fat ( or "pararenal fat

• peritoneum ( anteriorly), and transversalis fascia posteriorly

Types of renal haemorrhege

according to the site:

• Intra-renal .

• Sub-capsular.

• Peri-renal.

Classification of Injury

Grade I

• Contusion

– Hematuria

– Urologic studies N

• Hematoma

– Subcapsular

– Non expanding

– Parenchyma N

Grade II

• Hematoma

– Perirenal

– Nonexpanding

• Laceration

– < 1.0 cm

– Renal cortex only

– No urinary

extravasation

Grade III

• Laceration

– > 1.0 cm

– Renal cortex only

– No urinary

extravasation

– Intact collecting

system

Grade IV

• Laceration

– Renal cortex

– Renal medulla

– Collecting system

• Vascular

– Main renal

artery/vein injury

with contained

hemorrage.

Grade V

• Completely

shattered kidney.

• Avulsion of renal

hilum (pedicule)

which

devascularizes

kidney.

Kennon et al. Radiographic assessment of renal trauma: our 15-year

experience. The Journal of Trauma, 154: 353-355; August 1995.

Pedicule Injury

Category I Renal contusion

Category I Subcapsular hematoma

Category I Simple renal laceration

Category I Subsegmental renal infarction

Category II Major renal laceration involving the collecting sysem

Category III Multiple renal laceration (Shattered Kidney)

Category III Traumatic occlusion of main renal artery

Category IV Ureteropelvic junction injuries

Coil embolization of the right renal artery

Renal contusion : (category 1) .focal area of

decreased contrast enhancment in the interpolar

region of left kidney

Subcapsular haematoma (category 1)

subcapsular fluid collection flattening the

posterolateral contour of the left kidney. There is

minimal cortical laceration

Simple renal laceration (category I) small hypoattenuating

laceration crossing the interpolar region of the left kidney

assocaited with perinephric collection . also hepatic laceration

and haemoperitoneum in the morrison pouch

Subsegmental renal infarction (category I ) sharply

demarcated wedge interpolar region of right kidney

note also subtle haemorrhage in right renal hilum

Major renal laceration involving the collecting

system (category II) .large distracted renal

fracture through the interpolar portion of right

kidney with dye extravasation

Multiple renal laceration (category III) .several

deep laceration of the interpolar region of the

right kidneyassociated with areas of active arterail

extravasation

Schattered kidney (category III)devitalized upper pole of the

right kidney due to degmentalk infarction(R) .note the

perinephric hyperattenuating blood clot (arrow) .also flattened

IVC indicate hypovolaemic shock

Traumatic occlusion of the main renal artery (category III). IVP

demonstrated poor visualization of the left kidney . CT show rim

enhancment of the outer cortex of the left kidney .DSA show

Ttaperd occlusion of proximal left main renal artery

Traumatic occlusion of right main renal artery .CT

show no enhancment of right kidney

(infarcted).retrograde opacification of renal vein .

Angiogram shows occlusuion of main renal artery

Ureteropelvic junction laceration with pre-existing

obstruction (category IV)

pelviectasis,blood clot in the renal pelvis,periureteral

urinoma,perinephric extravasation

The capsule maintains the reniform contour as a hematoma compresses the kidney. This subcapsular renal hematoma is consistent with an acute process, which is hypoechoic with some mixed echoes caused by the early deposit of fibrin

• haematoma perinephric

Axial CT section without intravenous contrast, showing a relatively hyperdense rightsided subcapsular haematoma (arrow). b. Axial contrast CT section demonstrates the right kidney is compressed with a delayed nephrogram relative to the left kidney.

Contrast enhanced CT of the abdomen demonstrates a moderate-sized left subcapsular hematoma which compresses the renal parenchyma (arrow). The left nephrogram is slightly diminished and there is no excretion of contrast by the left kidney. A wedge-shaped low density laceration is seen in the anterior midpole of the left kidney (arrow). There is mild infiltration of the left perinephric fat (arrow), but no large perinephric hematoma is seen.

Perirenal hematoma

Truma of horse show kidney (MRI)

With urinoma

Associations with renal injury

: Fractures of the lower ribs transverse processes of the

spine;

posterior abdominal wall and psoas sheath hematomas.

Adrenal gland injury: is rare, The Imaging of choice is CT showing adrenal hemorrhage, adrenal contusion and laceration and veiling of the periadrenal fat.

Right perinephric haematoma . Renal vessels visible . Poor

uptake of contrast

Axial CT scan showing perinephric haematoma following trauma to a

previously unrecognised obstructive hydronephrosis

CT examination: Unenhanced (on the left side) and contrast-enhanced (on the right side),

axial scans: In the plain scan, well-defined subcapsular fluid can be observed on the dorsal

surface of the left kidney (arrow). In the right picture, after the intravenous injection of contrast

material, the renal parenchyma and the renal capsule can be better differentiated from the

haemorrhage (arrow).

Axial contrast-enhanced CT section through the kidneys showing extravasation

of contrast (arrow) from the left kidney, due to traumatic forniceal rupture.

Blunt renal trauma. Entire collecting system, ureter and

bladder filled with a blood clot.

G5

Devascularisation of left kidney

Renal Trauma Images - Devascularised Kidney

Classification: Grade 5

Other Problems to be Considered:

• Renal pseudofracture

Renal pseudocapsular hematoma

Renal pseudoextravasation

Renal tumor with hemorrhage

Hematoma of extrarenal origin

dissecting into the Gerota space

• contusions are perceived as ill-

defined or sometimes sharply

marginated areas of reduced

enhancement and excretion

Kidney trauma. Grade 2 renal injury, subcapsular and perinephric hematomas. Contrast-enhanced CT scan of the abdomen on a patient with hematuria after a motor vehicle

collision shows an ill-defined fluid collection in the left perinephric space. There is also a subcapsular hematoma with deformity of the renal parenchyma.

Kidney trauma. Grade 2 renal injury, perinephric hematoma. Contrast-

enhanced CT scan of the abdomen on a patient with hematuria after a motor

vehicle collision shows an ill-defined fluid collection in the left perinephric space

Kidney trauma. Grade 3 renal laceration. CT scan of the abdomen after intravenous contrast administration shows

irregular nonenhancing renal parenchymal defect with extension greater than 1 cm deep to near the renal pelvis. Delayed

image showed no urinary contrast extravasation

Kidney trauma. Grade 4 renal injury segmental infarction. Contrast-enhanced

CT scan of the upper abdomen shows a segmental area of nonenhancement in

the upper medial left kidney without associated renal laceration.

Kidney trauma. Grade 4-5 renal injury. Lacerations extending to the collecting system.

Contrast-enhanced CT scan of the abdomen in a patient with hematuria after a motor

vehicle collision shows deep lacerations extending into the collecting system of the right

kidney. Extension into the collecting system is confirmed by urinary contrast

extravasation on delayed image through the kidney in excretory phase

Grade 5 renal injury. Shattered left kidney. Contrast-enhanced CT scan of the

abdomen in a patient with hematuria after a motor vehicle collision shows several deep

lacerations extending into the collecting system of the left kidney with separation of the fragments

Grade 5 renal injury. Partial ureteropelvic junction tear and multiple deep

lacerations. Contrast-enhanced CT scan of the abdomen in a patient involved in

a motor vehicle collision shows multiple deep renal lacerations with perinephric

fluid extending into the renal hilum

Delayed image shows

urinary contrast extravasation

development of a

urinoma, in spite of initial

treatment with stent

placement

Grade 5 renal injury. Shattered kidney. Contrast-enhanced CT scan of

the abdomen in a patient with hematuria and hypotension after a motor vehicle collision

shows transection of the right kidney with a large hematoma around and between the 2

halves of the kidney. The 2 halves are both perfused because there were 2 renal arteries

Delayed images show urinary contrast extravasation

Grade 5 renal injury. Shattered kidney with renal vein thrombosis (incomplete).

Abdominal radiograph after intravenous contrast administration shows absent

right nephrogram. CT scan (Image 35) shows shattered kidney and renal vein

thrombus extending slightly into the inferior vena cava.

Grade 5 renal injury, devascularization.

Contrast-enhanced CT scan of the abdomen

in a 52-year-old man after an assault shows

dissection of the origin of the left renal

artery, with no perfusion of the left kidney.

Also, a hematoma can be noted along the

anterior renal fascia Four-week follow-up shows no change, ie,

no trace of renal cortical rim enhancement.

An adjacent cystic hematoma along the

anterior renal fascia persists

After four weeks a small "pool" of layering contrast extravasated

into the hematoma

Kid trauma. Active vascular contrast extravasation. A

male of unknown age after a motor vehicle

collisionwith hematuria and hypotension. CT scan of

the abdomen with contrast shows a small upper pole

laceration on the left with large perinephric

hematomaand a tiny "flame" of intravenous contrast

extravasation..

Kidney trauma. Active vascular contrast extravasation. A 35-year-old man presented

with hypotension and hematuria following a motor vehicle accident. This contrast-

enhanced CT scan shows a perinephric hematoma with central high attenuation,

which probably represents active bleeding

Intravenous and oral contrast

material

• Intravenous contrast enhancement is essential

for abdominal CT. Without intravenous contrast

enhancement, solid-organ injuries such as

renal lacerations can often be imperceptible. In

addition, active arterial extravasation is only

detectable with intravenous contrast material

Perinephric haematoma

RENAL ARTERY OCCLUSION AFTER ABDOMINAL TRAUMA