This document discusses nuclear medicine techniques for evaluating the genitourinary system, including the kidneys and bladder. It describes radiopharmaceutical agents such as DTPA, MAG3, DMSA, and GH that are used to evaluate glomerular filtration rate, renal blood flow, renal anatomy, and detect any obstruction. It also discusses the indications, interpretation of renograms, and techniques for assessing renal artery stenosis using ACE inhibitors.

1. GENITOURINARY SYSTEM
MOHAN MAKHIJA, M.D.

2. RADIONUCLIDE GU
EVALUATION
• QUANTITATIVE EVALUATION OF
RENAL PERFUSION AND FUNCTION
• RENAL ANATOMY -ULTRASOUND AND
CT.
• RENAL IMAGING CONFINED TO
FUNCTIONAL ANALYSIS

3. INDICATIONS
• SENSTIVITY TO CONTRAST MATERIAL
• ASSESSMENT OF RENAL FLOW
• DIFFERENTIAL FUNCTIONAL
ASSESSMENT
• URETERAL OR PELVIC OBSTRUCTION
• VESICOURETERAL REFLUX
• RENOVASCULAR HYPERTENSION

4. EXCRETORY FUNCTION
• TWO PRIMARY MECHANISIMS
• A) PASSIVE FILTRATION THROUGH
THE GLOMERUS
• B) ACTIVE SECRETION BY THE
TUBULES

5. Renal Anatomy
Thrall and Ziessman Nuclear Medicine THE REQUISITES

6. DTPA
• DTPA -CLEARED BY GLOMERULAR
FILTRATION -MEASURE GFR
• NORMAL GFR IS 125 ML/MIN

7. Renal Anatomy and Function
Thrall and Ziessman Nuclear Medicine THE REQUISITES

8. MAG 3
• MAG 3 NEARLY IDENTICAL TO
HIPPURAN
• IN PRACTICE, 99m Tc-DTPA
• 99m Tc-MAG 3 ARE ROUTINELY USED.

9. Mechanisms of Uptake for Renal Scintigraphic Agents
UPTAKE MECHANISM IMAGING AGENT
Glomerular filtration (100%) Tc99m DTPA
Tubular (100%) Tc99m MAG3
Tubular (80%) and glomerular (20%) I-131 and I-123 OIH
Cortical binding (50%) Tc99m DMSA
Glomerular filtration (80%) Tc99m GHA
and cortical binding (20%)
Thrall and Ziessman Nuclear Medicine THE REQUISITES

10. GFR WITH DTPA
• Tc DTPA USED FOR EVALUATING GFR
• SERIAL IMAGES – SIMILAR TO IVP.
• ACCURATE ESTIMATE OF GFR.
• 90% OF DTPA –FILTERED BY 4 HOURS
• NORMAL DOSE 10-20 mCi I.V.

11. RENAL CORTICAL AGENTS
• DMSA AND GLUCOHEPTONATE
• DMSA EXCELLENT CORTICAL AGENT
• 40% OF DOSE IN CORTEX AT 6
HOURS.
• ONLY 10% OF TRACER IN URINE.
• BINDS TO SULFHYDRYL GROUPS IN
PROXIMALTUBULES

12. ANATOMIC (CORTICAL)
IMAGING
• USUALLY PERFORMED FOR:
• SPACE OCCUPYING LESIONS
• PSEUDOTUMORS - COLUMNS OF
BERTIN.
• EDEMA OR SCARRING – ACUTE
CHRONIC PYELONEPHRITIS
• DMSA OR GH USING PINHOLE/SPECT

16. RADIONUCLIDE RENAL
EVALUATION
• VISUAL ASSESSMENT OF PERFUSION
AND FUNCTION
• RENOGRAPHY (TIME ACTIVITY
CURVES REPRESENTATIVE OF
FUNCTION)
• QUANTIFICATION OF RENAL
FUNCTION (GFR AND ERPF)
• ANATOMIC IMAGING (RENAL CORTEX)

17. RENAL FUNCTION IMAGING
• DYNAMIC OR SEQUENTIAL STATIC, 3-5
MINUTE DTPA OR MAG3 IMAGES
OVER 20-30 MINUTES.
• MAXIMAL PARENCHYMAL ACTIVITY
SEEN AT 3-5 MINUTES.
• ACTIVITY IN COLLECTING SYSTEM
AND BLADDER BY 4-8 MINUTES.

20. RENOGRAPHY
• RENOGRAM IS SIMPLY A
TIMEACTIVITY CURVE - GRAPHIC OF
UPTAKE AND EXCRETION BY THE
KIDNEYS.
• CLASSIC RENOGRAM CURVE IS
OBTAINED BY USING Tc-MAG3
(TUBULAR SECRETION AGENT)

21. NORMAL RENOGRAM CURVE
• THREE PHASES:
• FIRST PHASE : VASCULAR TRANSIT
FOR 30-60 SECONDS. REPRESENTS
THE INITIAL ARRIVAL OF THE
RADIOPHARMACEUTICAL IN EACH
KIDNEY.

23. NORMAL RENOGRAM CURVE
• SECOND PHASE:
• CORTICAL OR TUBULAR
CONCENTRATION PHASE OF INITIAL
PARENCHYMAL TRANSIT.
• OCCURS DURING 1-5 MINUTES AND
CONTAINS THE PEAK OF THE CURVE.

25. NORMAL RENOGRAM CURVE
• THIRD PHASE:
• CLEARANCE OR EXCERETION PHASE.
REPRESENTS THE DOWN SLOPE OF
THE CURVE AND IS PRODUCED BY
EXCRETION OF THE TRACER FROM
THE KIDNEY AND CLEARANCE FROM
THE COLLECTING SYSTEM.

27. RENOGRAM DATA
• TIME TO PEAK ACTIVITY. NORMAL IS
ABOUT 3-5 MINUTES.
• RENAL UPTAKE RATIOS AT 2-3
MINUTES. IDEALLY 50% EACH.
• 40% OR LESS IN ONE KIDNEY
SHOULD BE CONSIDERED AS
ABNORMAL.

28. RENOGRAM DATA
• HALF-TIME EXCRETION IS THE TIME
FOR HALF OF THE PEAK ACTIVITY TO
BE CLEARED FROM THE KIDNEY.
NORMAL IS 8-12 MINUTES

29. RENOGRAM DATA
• 20 MINUTE TO PEAK RATIO.
• THIS IS ACTIVITY MEASURED IN EACH
KIDNEY AT 20 MINUTES AND IS EXPRESSED
AS A PERCENTAGE OF PEAK CURVE
ACTIVITY.
• IN ABSENCE OF PELVIC CALYCEAL
RETENTION OR IF ONLY CORTICAL ROI IS
USED, A NORMAL 20 MINUTE MAXIMAL
CORTICAL RATIO IS <0.3 OR 30%

30. RENOGRAM DATA
• 20 MINUTE TO PEAK COUNT RATIO
• AS RENAL FUNCTION DETERIORATES,
DELAYED TRANSIT - RESULTS IN AN
ABNORMAL RENOGRAM CURVE,
WHICH CAN BE QUANTITATED BY
USING THIS INDEX.

34. QUANTITATION OF RENAL
FUNCTION
• UP TO HALF OF RENAL FUNCTION,
INCLUDING GFR, MAY BE LOST
BEFORE SERUM CREATININE LEVELS
BECOME ABNORMAL
• DIRECT MEASUREMENT OF GFR AND
ERPF, PLAYS AN IMPORTANT ROLE IN
ASSESSMENT OF RENAL FUNCTION.

35. RENAL ARTERY STENOSIS
• SIGNIFICANT RENAL ARTERY
STENOSIS (60% TO 75%) DECREASES
AFFERENT ARTERIOLAR BLOOD
PRESSURE
• THIS STIMUALTES RENIN SECRETION
BY JUXTAGLOMERULAR APPARATUS
• RENIN ELICITS PRODUCTION OF
ANGIOTENSIN I

36. RENAL ARTERY STENOSIS
• ANGIOTENSIN I IS ACTED ON BY ACE
TO YIELD ANGIOTENSIN II
• ANGIOTENSIN II INDUCES
VASOCONTRICTION OF THE
EFFERENT ARTERIOLES, WHICH
RESTORES GFR PRESSURE AND
RATE.

37. ACE-I (Captopril) Renography
Angiotensin Converting Enzyme –Inhibitor
Renin – angiotensin –aldosterone axis
Thrall and Ziessman Nuclear Medicine THE REQUISITES

38. RENAL ARTERY STENOSIS
• ACE INHIBITORS - CAPTOPRIL AND
ENALAPRILAT, PREVENT THE
PRODUCTION OF ANGIOTENSIN II
• PREGLOMERULAR FILTRATION
PRESSURES ARE NO LONGER
MAINTAINED
• RESULTS IN SIGNIFICANT DECREASE
IN GLOMERULAR FILTRATION.

39. ACE-I Renography - RVH
Thrall and Ziessman Nuclear Medicine THE REQUISITES

40. ACE INHIBITION
• PATIENTS SELECTION - LIMITED TO-
MODERATE TO HIGH PROBABILITY OF
RENOVASCULAR HYPERTENSION.
• INITIAL PRESENTATION OF
HYPERTENSION IN PATIENTS OLDER
THAN 60 YEARS OR YOUNGER THAN
20YEARS

41. ACE INHIBITION
• SEVERE OR ACCELERATED HTN
RESISTANT TO MEDICATION THERAPY
• HTN PREVIOUSLY WELL CONTROLLED
BUT NOW DIFFICULT TO MANAGE
• HTN IN PATIENTS WITH OTHER
EVIDENCE OF VASCULAR DISEASE
• UNEXPLAINED HTN IN PATIENTS WITH
ABDOMINAL BRUITS

42. ACE INHIBITORS
• DISCONTINUE CAPTOPRIL – 48
HOURS
• ENALAPRILAT FOR 1 WEEK
• MAINTAIN - IF DEEMED NECESSARY
AND INADVISABLE TO DISCONTINUE
• REFRAIN FROM ACEI MEDICATION ON
THE DAY OF THE STUDY
• ANTIHYPERTENSIVE DRUGS OF NON-
ACE INHIBITOR CLASSES - OK

43. PROTOCOL
• SHOULD BE FASTING – ABSORPTION
• 25 TO 50 MG OF ORAL CAPTOPRIL
• BLOOD PRESSURE EVERY 15 MIN/HR
• ALTERNATIVE – IV ENALAPRILAT
(VASOTEC) 0.04 MG/KG – MAX 2.5 MG
OVER 3 TO 5 MIN

44. SCINTIGRAPHY
• ONE HOUR AFTER CAPTOPRIL OR
15 MIN AFTER ENALAPRILAT INFUSION
10 mCi 99M Tc-MAG3 OR 99M Tc-DTPA
SOME PROTOCOLS USE IV 40-60 mg OF IV
FUROSEMIDE.
AT TERMINATION - FINAL BOOD PRESSURE
SHOULD BE OBTAINED

47. PRECAUTIONS
• IN PATIENTS WITH UNILATERAL
STENOSIS AND RENAL INSUFF.
• BILATERAL RAS
• SOLITARY KIDNEY OR TRANSPLANT
• CAPTOPRIL OR ENALPRILAT SHOULD
BE USED ADVISEDLY FOR DIAGNOSIS
• MAINTAIN IV ACESS THROUGHOUT
THE STUDY

48. ? ONE DAY ? TWO DAY
• DIAGNOSIS OF RAS DEPENDS ON
INDUCTION OR WORSENING OF
RENAL DYSFUNCTION AFTER ACEI
• A BASELINE STUDY IS EXTREMELY
USEFUL – ASSESSING EFFECT OF
MEDICATION ON RENAL FUNCTION

49. ONE STAGE PROTOCOL
• ONE STAGE PROTOCOL – PATIENTS
WITHOUT EVIDENCE OF PRE-
EXISTING RENAL DYSFUNCTION
• CAPTOPRIL CHALLENGE STUDY
PERFORMED FIRST.
• IF NORMAL, A DIAGNOSIS OF RVH IS
UNLIKELY (10%). NO BASELINE

50. DIAGNOSTIC CRITERIA
• HALLMARK OF RVH IS A POST-CAP
RENOGRAM - ABNORMAL OR MORE
ABNORMAL THAN A BASELINE
RENOGRAM WITHOUT CAPTOPRIL
• USING 99M Tc 99m DTPA THE
PRINCIPAL FINDING IS DROP IN GFR

51. SINGLE DAY – TWO STAGE
• BASELINE NONCAPTOPRIL STUDY
WITH LOW DOSE 1-2 mCi OF Tc-MAG3
• 40 mg OF FUROSEMIDE AFTER FIRST
STUDY-GOOD WASHOUT OF ACTIVITY
• REPEAT STUDY USING CAPTOPRIL
SEVERAL HOURS LATER

52. QUANTITATIVE PARAMETERS
• % OF UPTAKE AT 2-3 MINUTES BY
ONE KIDNEY < 40% OF TOTAL
• RETAINED CORTICAL ACTIVITY AT 20
MIN DIFFERING BY >20% OR
INCREASE FROM THE BASELINE
STUDY OF 0.15 (NORMAL <0.3)
• DELAY IN TTP ACTIVITY OF MORE
THAN 2 MIN FROM BASELINE STUDY.

53. BILATERAL RAS
• BILATERAL ABNORMALITIES OR
WORSENING FROM BASELINE.
• DETECTION IS MORE DIFFICULT
• BIL RAS OFTEN BEHAVES IN
ASYMMETRIC WAY TO ACEI,
THEREFORE DISTINGUISHABLE FROM
CHRONIC PARENCHYMAL RENAL DIS.

54. S AND S
• SENSTIVITY AND SPECIFICITY OF ACEI
RENOGRAPHY SURPASS 90%.
• FALSE +VE STUDIES ARE UNCOMMON
• ABNORMALITIES WITH ACEI BEST
SEEN IN RAS OF 60%-90%
• LACK OF SIGNIFICANT RENIN-
ANGIOTENSIN COMPENSATION <60%

55. OBSTRUCTIVE UROPATHY
• ROUTINE RENOGRAPHY MAY NOT
DIFFERENTIATE OBSTRUCTION FROM
HYDRONEPHROSIS OF A
NONOBSTRUCTIVE NATURE.
• DIURETIC RENOGRAPHY DISTINGUISH
DILATATION FROM OBSTUCTION.

56. Diuretic Renography in Children
Indications:
UPJ, UVJ obstruction
Hydronephrosis
Post-surgical evaluation
Distention collecting system and back pain
SNM: Procedure Guideline

58. Diuretic Renography in Children
Interpretation criteria – T ½ washout
F+20
T ½ <10 min absence of obstruction
T ½ 10-20 min equivocal
T ½ 10-15 min probably normal
T ½ >20 min obstructed
F-15
T ½<20 min non-obstructed
SNM: Procedure Guideline

64. PRE LASSIX

65. POST LASIX

66. Renal Transplants
Flow
Function
Obstruction
Leak
Tc99m MAG3 preferred over Tc99m DTPA

68. Renal Transplant
Post operative
ATN: flow good
function decreased

72. Nuclear Cystogram - Reflux Grade
Thrall and Ziessman Nuclear Medicine THE REQUISITES

79. HIPPURAN
• EVALUATION - TUBULAR SECRETION -
WITH HIPPURAN
• 80% -TUBULAR SECRETION. (ABOUT
20%) THROUGH GFR.

80. RADIOPHARMACEUTICALS
• TUBULAR SECRETION – HIPPURAN –
MAG 3
• GLOMERULAR FILTRATION – DTPA
• RENAL TUBULES - CORTICAL IMAGING
DMSA AND GLUCOHEPTONATE

81. RENAL PERFUSION IMAGING
• 10-20 mCi DTPA OR MAG3 I.V.
• SERIAL IMAGES 1-5 SECONDS
• ACTIVITY IN KIDNEYS ABOUT 1 SCOND
AFTER THE ABDOMINAL AORTA.
• TIME ACTIVITY CURVES REFLECT
RENAL PERFUSION- FIRST MINUTE

82. TUBULAR SECRETION AGENTS
• IODINE-131 ORTHOIODOHIPPURATE -
99m Tc-MAG3 USED CLINICALLY
• 95% CLEARED BY PROXIMAL
TUBULES
• EXTRACTION 40% TO 50% (MORE
THAN TWICE OF DTPA)
• CLEARANCE MAG3 - FOR ERPF
• DOSE 10-20 mCi I.V.

83. RENAL CORTICAL AGENTS
• DOSE OF DMSA 1-5 mCi I.V.
• HIGH RADIATION DOSE TO THE
KIDNEYS (LONG EFFECTIVE T ½)
• DELAYED IMAGES AT 1-3 HOURS.
• DMSA HAS SHORT SHELF-LIFE.

84. RENAL CORTICAL AGENTS
• GH IS CLEARED GFR AND RT
• EARLY IMAGES RENAL PERFUSION,
COLLECTING SYSTEMS AND URETERS
• RENAL CORTEX -WELL VISUALIZED
2-4 HOURS AFTER INJ.
• 10-15% IN RENAL TUBULES -40% IN
URINE AT 1 HOUR
• DOSE 10-20 mCi I.V.

85. QUANTITATION OF RENAL
FUNCTION
• THE CLASSIC MEASURES OF RENAL
FUNCTION - ABILITY OF THE KIDNEYS TO
CLEAR CERTAIN SUBSTANCES FROM THE
PLASMA.
• CLEARANCE OF INULIN, WHICH IS ENTIRELY
FILTERED, DEFINES GFR.
• CLEARANCE OF PARA AMINOHIPPURATE
WHICH IS BOTH FILTERED AND SECRETED
BY THE TUBULES, DEFINES RPF

86. QUANTITATION OF RENAL
FUNCTION
• RADIOPHARMCEUTICAL FOR THESE
CLEARANCES ARE 99mTc-DTPA FOR
INULIN CLEARANCE AND GFR.
• 99mTc-MAG3 - PRIMARILY SECRETED
BY THE TUBULES, FOR PAH
CLEARANCE AND ERPF.