CT CT UrographyUrographyStuart G. Silverman, M.D.Stuart G. Silverman, M.D.

Professor of RadiologyProfessor of RadiologyHarvard Medical SchoolHarvard Medical School

Director, Abdominal Imaging Director, Abdominal Imaging and Interventionand Intervention

Brigham and WomenBrigham and Women’’s s HospitalHospital

Boston, MABoston, MA

CT CT UrographyUrographyStuart G. Silverman, M.D.Stuart G. Silverman, M.D.

Disclosure of financial Disclosure of financial relationship with relevant relationship with relevant commercial interestcommercial interestSiemens Medical SolutionsSiemens Medical SolutionsMalverneMalverne , PA , PA –– Consultant Consultant

OutlineOutline••How to do a CT How to do a CT urogramurogram••When it should be performedWhen it should be performed••Why CT Why CT urographyurography is the is the test of choice (with case test of choice (with case examples)examples)

••SummarySummary

10 mg 10 mg IV Furosemide 22--33”” CM (100cc)

UnenhancedUnenhanced NephrographicNephrographic ExcretoryExcretoryRangeRange Abd/PelAbd/Pel KidneysKidneys Abd/PelAbd/PelDelay Delay ---- 100 s 100 s 10 10 -- 15 min15 minCollimation Collimation 1.2 mm 1.2 mm 1.2 mm 1.2 mm 0.6 mm0.6 mmAxial Recon/Axial Recon/IncrIncr 3/3 3/1.5 3/3 3/1.5 3/33/3Post Processing Post Processing ---- ---- CorCor / Sag / MIP / CPR / VR/ Sag / MIP / CPR / VR

Iodinated contrast material (300 Iodinated contrast material (300 mgImgI/ml); 0.5 s rotation time/ml); 0.5 s rotation timeAEC w/ quality reference 200 AEC w/ quality reference 200 mAsmAs, 120 , 120 kVpkVp

BWH CT Urography Protocol64 64 –– ChannelChannel MDCT with 3 phasesMDCT with 3 phases

Silverman et al Radiology 2006Silverman et al Radiology 2006

Problem Imaging the Problem Imaging the UrotheliumUrothelium

It is difficult to obtain a It is difficult to obtain a single image of all urinary single image of all urinary collecting system segments collecting system segments in an in an opacifiedopacified and and distended state.distended state.

……The The uretersureters peristalseperistalse!!

Use Use FurosemideFurosemide……FurosemideFurosemide diuresisdiuresis is is predominantly due to inhibition of predominantly due to inhibition of NaClNaCl reabsorptionreabsorption in the thick in the thick ascending limb of ascending limb of HenleHenle

Increases urinary flow rateIncreases urinary flow rate

•• FurosemideFurosemide allergyallergy•• Sulfa allergySulfa allergy•• SBP < 90 SBP < 90 torrtorr

IV IV FurosemideFurosemide WithheldWithheld

IV Saline is suitable alternativeIV Saline is suitable alternative

CM (100cc) IV Saline(250 IV Saline(250 ccsccs))

UnenhancedUnenhanced NephrographicNephrographic ExcretoryExcretoryRangeRange Abd/PelAbd/Pel KidneysKidneys Abd/PelAbd/PelDelay Delay ---- 100 s 100 s 10 10 -- 15 min15 minCollimation Collimation 1.2 mm 1.2 mm 1.2 mm 1.2 mm 0.6 mm0.6 mmAxial Recon/Axial Recon/IncrIncr 3/3 3/1.5 3/3 3/1.5 3/33/3Post Processing Post Processing ---- ---- CorCor / Sag / MIP / CPR / VR/ Sag / MIP / CPR / VR

Iodinated contrast material (300 Iodinated contrast material (300 mgImgI/ml); 0.5 s rotation time/ml); 0.5 s rotation timeAEC w/ quality reference 200 AEC w/ quality reference 200 mAsmAs, 120 , 120 kVpkVp

BWH CT Urography Protocol64 64 –– ChannelChannel MDCT with 3 phasesMDCT with 3 phases

McTavishMcTavish et al Radiology 2002et al Radiology 2002

•• Both IV Both IV furosemidefurosemide and IV and IV saline are safesaline are safe•• No adverse events with over 8 No adverse events with over 8 years of use of IV saline (> 3000 years of use of IV saline (> 3000 administrations), and over 5 administrations), and over 5 years of IV years of IV FurosemideFurosemide (> 2000 (> 2000 administrations)administrations)

Safety Record at BWHSafety Record at BWH

Evaluating the Evaluating the UrotheliumUrotheliumItIt’’s not just about depicting s not just about depicting the anatomy. the anatomy. OpacificationOpacificationand distension helps detect and distension helps detect small cancers!small cancers!

Evaluating the Evaluating the UrotheliumUrothelium““Why be concerned about Why be concerned about opacifyingopacifying and distending and distending the the uretersureters? If a tumor is ? If a tumor is present, it will cause present, it will cause obstruction, wonobstruction, won’’t it?t it?””

71 71 yomyom w/ Gross w/ Gross HematuriaHematuriaPapillary tumor (in crossPapillary tumor (in cross--section) in section) in ureteralureteral lumenlumen

Note space for urine to flow around the tumorNote space for urine to flow around the tumor

DonDon’’t assume t assume unobstructed collecting unobstructed collecting systems are normal!systems are normal!

Evaluating the Evaluating the UrotheliumUrotheliumWhat about the bladder? What about the bladder? Bladder cancer is the most Bladder cancer is the most common malignancy of the common malignancy of the urinary tract, by far.urinary tract, by far.

Bladder issuesBladder issues……•• DistensionDistension is needed to assess for masses is needed to assess for masses

and wall thickeningand wall thickening•• OpacificationOpacification of urine maximizes CNR and of urine maximizes CNR and

helps detect masseshelps detect masses•• MixingMixing of contrast media and urine of contrast media and urine

provides homogeneous background from provides homogeneous background from which masses can be detectedwhich masses can be detected

FurosemideFurosemide and saline help with all threeand saline help with all three……

BWH MDCT Urography ProtocolPatient PreparationPatient Preparation

•• None needed prior to arrivingNone needed prior to arriving(no bowel preparation)(no bowel preparation)

•• Drink 900 cc water instead of Drink 900 cc water instead of oral contrastoral contrast

•• VOID prior to exam!VOID prior to exam!

BWH CTU Protocol for pts < 40 y.o.BWH CTU Protocol for pts < 40 y.o.

Split dose Split dose 370 370 mgImgI/ml/ml CM (40cc) (80 cc)UnenhancedUnenhanced NPNP + + EPEP

RangeRange Abd/PelAbd/Pel Abd/PelAbd/PelDelay Delay ---- 6 min6 min 100 sec100 secCollimation 2.5 mm Collimation 2.5 mm 2.5 mm2.5 mmAxial Recon/Axial Recon/IncrIncr 3/3 3/3 3/33/3Post Processing Post Processing ---- CorCor / Sag / MIP / CPR / VR/ Sag / MIP / CPR / VR

Modified from Chow and Modified from Chow and SommerSommer AJR 2001AJR 2001

SalineSaline

Obtaining NP and PP during one Obtaining NP and PP during one scan reduces radiation dosescan reduces radiation dose

BWH CTU Protocol for pts < 40 y.o.BWH CTU Protocol for pts < 40 y.o.

Split dose Split dose 370 370 mgImgI/ml/ml CM (40cc) (80 cc)UnenhancedUnenhanced NPNP + + EPEP

RangeRange Abd/PelAbd/Pel Abd/PelAbd/PelDelay Delay ---- 6 min6 min 100 sec100 secCollimation 2.5 mm Collimation 2.5 mm 2.5 mm2.5 mmAxial Recon/Axial Recon/IncrIncr 3/3 3/3 3/33/3Post Processing Post Processing ---- CorCor / Sag / MIP / CPR / VR/ Sag / MIP / CPR / VR

Modified from Chow and Modified from Chow and SommerSommer AJR 2001AJR 2001

Obtaining NP and PP during one Obtaining NP and PP during one scan reduces radiation dosescan reduces radiation dose

FurosemideFurosemide

•• Fractionates contrast effects:Fractionates contrast effects: less less contrast available to contrast available to opacifyopacifycollecting systemcollecting system

•• UretersUreters and bladder not imaged and bladder not imaged optimally (needs supplementation)optimally (needs supplementation)

•• Beam hardening in kidneys (if no Beam hardening in kidneys (if no furosemidefurosemide))

•• Modest dose savingsModest dose savings

Why not splitWhy not split--dose contrast?dose contrast?

Radiation DoseRadiation Dose•• ThreeThree--phase acquisition CTU phase acquisition CTU

compared to IVU with full compared to IVU with full nephrotomographynephrotomography

•• Measured (TLD) skin and Measured (TLD) skin and calculated calculated effeff. dose (. dose (mGymGy) )

•• Mean Mean effeff. dose for CTU (14.8 . dose for CTU (14.8 mGymGy) is ) is 1.5 x1.5 x that for IVU (9.7 that for IVU (9.7 mGymGy))

Nawfel et al, Radiology 2004

•• BWH specific dataBWH specific data•• Results not Results not generalizablegeneralizable; ;

techniques for IVU and CTU techniques for IVU and CTU differ across institutionsdiffer across institutions

•• Need institutionNeed institution--specific data specific data oror standardized protocolsstandardized protocols

•• Data obtained without current Data obtained without current modulationmodulation

Radiation Dose Radiation Dose

Automatic Exposure Control (AEC)Automatic Exposure Control (AEC)

0

50

100

150

200

250

300

350

400

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500

0

50

100

150

200

250

mA attenuationtube current

shoulder

thoraxliver

0

20

40

60

80

100mAs per rotation(mean value 38mAs)

6 6 yoyo childchild

1165 65 mAsmAs reduced to 35 reduced to 35 mAsmAs

•• Variable Variable mAmAboth Inboth In--plane plane AND ZAND Z--axisaxis

•• Can decrease Can decrease meanmean mAsmAs

0 5 10 15 20 25 30 35 40 45 5002468

1012141618202224262830

AEC

No dose reduction(Ref. 7)

AP thickness (cm)

Effe

ctiv

e D

ose

(mSv

)CTU: AEC CTU: AEC vsvs No Dose ModulationNo Dose Modulation

AP AP ThkThk DoseDose20 cm20 cm ½½31.5 cm31.5 cm ==35 cm35 cm >>

AEC reduces radiation dose in small patients, however, dose may AEC reduces radiation dose in small patients, however, dose may actually increase in large patients to compensate for the increaactually increase in large patients to compensate for the increase se in image noisein image noise. When AEC is used, variation in dose depends on . When AEC is used, variation in dose depends on ““initial reference initial reference mAsmAs”” (or the noise factor setting) and patient (or the noise factor setting) and patient thickness.thickness.

Nawfel et al, AAPM 2006

CT CT UrographyUrography DefinitionDefinition•• A CT A CT urogramurogram is a CT examination is a CT examination of the entire urinary tract before of the entire urinary tract before and after the administration of IV and after the administration of IV contrast material and includes contrast material and includes excretory phase images.excretory phase images.

•• It is NOT any CT scan performed It is NOT any CT scan performed for a urinary tract complaint!for a urinary tract complaint!

Silverman, Silverman, LeyendeckerLeyendecker, Amis. Radiology 2009, Amis. Radiology 2009Van Van DerDer MolenMolen et al (ESUR) European Radiology 2007et al (ESUR) European Radiology 2007

Urinary Tract CT ProtocolsUrinary Tract CT Protocols•• Flank pain Flank pain -- > UP (> UP (““Stone protocolStone protocol””))•• Renal mass Renal mass -- > UP, NP, Excretory (Kidney)> UP, NP, Excretory (Kidney)•• Congenital anomalies Congenital anomalies -- > Excretory> Excretory•• Partial Partial nephrectomynephrectomy -- > AP, VP, Excretory> AP, VP, Excretory•• PostPost--operative Comp operative Comp -- > Excretory> Excretory•• Trauma Trauma --> NP, Excretory> NP, ExcretoryUP = UP = unenhancedunenhanced phase; NP = phase; NP = nephrographicnephrographic phasephaseAP = arterial phase; VP = venous phase AP = arterial phase; VP = venous phase

UrographicUrographic Tests of Choice:Tests of Choice:Historical PerspectiveHistorical Perspective

< '85< '85 '85'85--'95 >'95'95 >'95--2000 > 20002000 > 2000HematuriaHematuria IVU IVU IVUIVU IVU IVU CCTTRenal DonorRenal Donor IVUIVU IVUIVU CTCT CTCTColic (stones) Colic (stones) IVU IVU IVUIVU CT CT CTCTObstruction Obstruction IVUIVU USUS CT CT CTCTTraumaTrauma IVUIVU CT CT CT CT CTCTRenal massesRenal masses IVUIVU CTCT CTCT CTCTFever / InfectionFever / Infection IVUIVU CT CT CTCT CTCT

CT is the test of choice for most CT is the test of choice for most urinary tract complaints.urinary tract complaints.There is no longer a condition or There is no longer a condition or problem for which IVU is needed.problem for which IVU is needed.

Indications: CT Indications: CT UrographyUrography•• HematuriaHematuria•• Suspected Suspected urothelialurothelial cancer cancer

(e.g., positive urine cytology)(e.g., positive urine cytology)•• FollowFollow--up up urothelialurothelial cancercancer•• HydronephrosisHydronephrosis ?etiology?etiology•• Others (Others (egeg, ablation), ablation)

Risk Factors for Urologic DiseaseRisk Factors for Urologic Disease•• Age > 40 yearsAge > 40 years•• SmokingSmoking•• Gross Gross hematuriahematuria•• IrritativeIrritative voiding symptomsvoiding symptoms•• Urinary tract infectionsUrinary tract infections•• Exposure to carcinogens: pelvic Exposure to carcinogens: pelvic

irradiation, analgesic abuse, irradiation, analgesic abuse, cyclophosphamidecyclophosphamide, chemicals/dyes , chemicals/dyes (benzenes, aromatic amines)(benzenes, aromatic amines)

AUA 2001: High Risk PatientsAUA 2001: High Risk Patients

Upper tract imaging, cytology, Upper tract imaging, cytology, cystoscopycystoscopy

GrossfeldGrossfeld, et al, Urology 2001, 57:604, et al, Urology 2001, 57:604--610610

OneOne positive urine sediment positive urine sediment >> 3RBC/hpf3RBC/hpf

If negative, repeat W/U every yr x 3 yrsIf negative, repeat W/U every yr x 3 yrs

AUA 2001: Low Risk PatientsAUA 2001: Low Risk Patients

Upper tract imaging, cytology, Upper tract imaging, cytology, cystoscopycystoscopy

GrossfeldGrossfeld, et al, Urology 2001, 57:604, et al, Urology 2001, 57:604--610610

2 of 32 of 3 positive urine sediments positive urine sediments >> 3RBC/hpf3RBC/hpf

If negative, further W/U optionalIf negative, further W/U optional

AUA 2001: High Risk PatientsAUA 2001: High Risk Patients

Upper tract imaging, cytology, Upper tract imaging, cytology, cystoscopycystoscopy

AUA 2001: Low Risk PatientsAUA 2001: Low Risk Patients

Upper tract imaging, cytology, Upper tract imaging, cytology, cystoscopycystoscopyGrossfeldGrossfeld, et al, Urology 2001, 57:604, et al, Urology 2001, 57:604--610610

Imaging for Imaging for HematuriaHematuria: AUA : AUA ‘‘0101

Upper tract imaging recommendation:Upper tract imaging recommendation:

IVU or CTUIVU or CTU

GrossfeldGrossfeld, et al, Urology 2001, 57:604, et al, Urology 2001, 57:604--610610

Imaging for Imaging for HematuriaHematuria: ACR : ACR ‘‘0505ExamExam RatingRating CommentsCommentsCT CT UrographyUrography 88IVUIVU 8 8 US (renal/bladder)US (renal/bladder) 66 May miss May miss urothelialurothelial lesionslesionsRetro Retro PyelographyPyelography 55MR MR UrographyUrography 44CT (A/P)CT (A/P) 44 May follow IVU or USMay follow IVU or USAngiographyAngiography 44 To detect AVMTo detect AVMKUBKUB 22 May be coupled with USMay be coupled with USMRIMRI (A/P)(A/P) 22ScintigraphyScintigraphy 22Virtual Virtual cystoscopycystoscopy 22

ChoykeChoyke et al, ACR 2005et al, ACR 2005

Imaging Algorithm for Imaging Algorithm for HematuriaHematuriaMDCTUMDCTU

Renal cystRenal cyst Renal massRenal mass NormalNormal UrothelialUrothelial abnabn

Retro Retro PyelogramPyelogramMRIMRI

This simple, effective imaging This simple, effective imaging algorithm is rapidly becoming algorithm is rapidly becoming accepted in clinical practiceaccepted in clinical practice

CTU in pts < 40 w/ CTU in pts < 40 w/ HematuriaHematuria•• Significant findings found uncommonly Significant findings found uncommonly

[44 (22%) of 204][44 (22%) of 204]•• Of 44 significant causes found, 33 (75%) Of 44 significant causes found, 33 (75%)

were due to were due to urolithiasisurolithiasis•• All but 3 significant findings were seen on All but 3 significant findings were seen on

unenhancedunenhanced CT aloneCT alone•• All 3 cases had predisposing conditions!All 3 cases had predisposing conditions!•• 4 false positive CT 4 false positive CT urogramsurograms would not would not

have been found on have been found on unenhancedunenhanced CT CT SadowSadow et al RSNA 2007et al RSNA 2007

Findings Findings notnot seen w/ seen w/ unenhancedunenhanced CTCT•• Only 3 CT Only 3 CT urogramsurograms needed to detect:needed to detect:

Papillary necrosis Papillary necrosis (pt w/ known (pt w/ known neurogenicneurogenicbladder)bladder)Renal lymphomaRenal lymphoma (pt w/ known lymphoma (pt w/ known lymphoma who had extensive disease in the thorax)who had extensive disease in the thorax)UreteralUreteral disruptiondisruption: S/P hysterectomy, fluid : S/P hysterectomy, fluid seen, but excretory phase needed to confirm seen, but excretory phase needed to confirm urinary sourceurinary source

All had predisposing conditionsAll had predisposing conditionsSadowSadow et al RSNA 2007et al RSNA 2007

CTU in pts < 40 w/ CTU in pts < 40 w/ HematuriaHematuria

SadowSadow et al RSNA 2007et al RSNA 2007

Unless there is a predisposing Unless there is a predisposing condition, it may be appropriate condition, it may be appropriate to perform only to perform only unenhancedunenhanced CT CT in pts < 40 with in pts < 40 with hematuriahematuria

But more data are neededBut more data are needed……

•• Three phase Three phase –– UP (abdomen and pelvis), NP UP (abdomen and pelvis), NP (kidneys only), EP (abdomen and pelvis), (kidneys only), EP (abdomen and pelvis), supplemented with 10 mg supplemented with 10 mg furosemidefurosemide IVIV

Patients > 40 years oldPatients > 40 years old

•• Split bolus, two phase Split bolus, two phase –– abdomen and abdomen and pelvis, supplemented with 250 cc saline IVpelvis, supplemented with 250 cc saline IV

Patients Patients << 40 years old40 years old

Patients Patients with risk factors for malignancywith risk factors for malignancy

Patients Patients with no risk factors for malignancywith no risk factors for malignancy

•• UnenhancedUnenhanced CT alone if CT alone if << 40 years of age?40 years of age?

Tailor Use and Protocols further?Tailor Use and Protocols further?

CTU CTU vsvs RP for Upper Tract TCCRP for Upper Tract TCC

Sensitivity = 0.97, PPV = 0.79

Specificity = 0.93, NPV = 0.99

CT Urography

Sensitivity = 0.96, PPV = 0.87

Specificity = 0.97, NPV = 0.97

Retrograde Pyelography

n = 151n = 151TumorTumorpositivepositive

TumorTumornegativenegative

CTU CTU positivepositive 3131 88

CTU CTU negativenegative 11 111111

n = 143n = 143TumorTumorpositivepositive

TumorTumornegativenegative

RP RP positivepositive 2626 44

RP RP negativenegative 11 112112

Cowan et al 2007 BJUInt ePUBNPV (0.97) > PPV (0.79)NPV (0.97) > PPV (0.79)

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4343 3939

82 (3%) positive CT 82 (3%) positive CT urogramsurograms (n=2602)(n=2602)

PPV: 43/82 = 52%PPV: 43/82 = 52% Wheeler S et al, SUR 2008Wheeler S et al, SUR 2008

Is CTU Good in Detecting UT TCC?Is CTU Good in Detecting UT TCC?

Wheeler S et al, SUR 2008Wheeler S et al, SUR 2008

Is CTU Good in Detecting UT TCC?Is CTU Good in Detecting UT TCC?

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Large Mass(>5 mm)

Small Mass(</=5 mm)

UrothelialThickening

CTU + True +

36

29

17

0

29

14

PPV = 81%PPV = 81%

PPV = 0%PPV = 0%

PPV = 48%PPV = 48%

Is CTU Good in Detecting UT TCC?Is CTU Good in Detecting UT TCC?•• The PPV (52%) of CTU for detection of The PPV (52%) of CTU for detection of

upper tract malignancies is moderate, upper tract malignancies is moderate, as benign findings mimic canceras benign findings mimic cancer

•• Large (> 5 mm) masses are likely to be Large (> 5 mm) masses are likely to be cancerscancers

•• Small (Small (<< 5 mm) masses are unlikely to 5 mm) masses are unlikely to be cancersbe cancers

•• Urothelial thickening is just as likely to Urothelial thickening is just as likely to be benign as malignantbe benign as malignant

Wheeler S et al, SUR 2008Wheeler S et al, SUR 2008

Imaging Algorithm for Imaging Algorithm for HematuriaHematuriaMDCTUMDCTU

Renal cystRenal cyst Renal massRenal mass NormalNormal Urothelial Urothelial abnabn

Retro Retro PyelogramPyelogramMRIMRI

Note.Note.-- Retrograde Retrograde pyelographypyelographymay still be needed when CTU may still be needed when CTU is positive..is positive..

Thickening?Thickening?

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Urothelial CA

GrossHematuria

MicroscopicHematuria 0.984, n=2490.984, n=249

0.971, n=3730.971, n=373

0.769, n=1580.769, n=158

Bladder Ca Detection (n=838)Bladder Ca Detection (n=838)Negative Predictive Value of CTUNegative Predictive Value of CTU

SadowSadow et al Radiology 2008et al Radiology 2008

AUA 2001: Low Risk PatientsAUA 2001: Low Risk Patients

CT CT urographyurography, cytology, , cytology, cystoscopycystoscopy

GrossfeldGrossfeld, et al, Urology 2001, 57:604, et al, Urology 2001, 57:604--610610

2 of 32 of 3 positive urine sediments positive urine sediments >> 3RBC/hpf3RBC/hpf

If negative, further W/U optionalIf negative, further W/U optional

Possibly Possibly in the in the

futurefuture……

CT CT UrographyUrography: How?: How?

•• CT with MDCT aloneCT with MDCT alone•• Three phases if Three phases if >> 40 40 yoyo•• Two phases if < 40 Two phases if < 40 yoyo•• IV IV furosemidefurosemide (or saline)(or saline)

•• HematuriaHematuria•• Suspected TCCSuspected TCC•• TCC followTCC follow--upup•• HydronephrosisHydronephrosis ?etiology?etiology•• Others (e.g., ablation)Others (e.g., ablation)

CT CT UrographyUrography: When?: When?

••CT is the imaging test of CT is the imaging test of choice for most urologic choice for most urologic conditions conditions

••CTU is comprehensiveCTU is comprehensive••Radiation dose may be Radiation dose may be

comparable to IVUcomparable to IVU

CT CT UrographyUrography: Why?: Why?

•• CTU will play a greater role CTU will play a greater role in bladder cancer detection in bladder cancer detection

•• CTU doses will be reduced CTU doses will be reduced via dose modulation, and via dose modulation, and possibly dual energy CT possibly dual energy CT (virtual (virtual unenhancedunenhanced scan)scan)

CT CT UrographyUrography: Future: Future

Thank YouThank You