A 24-year-old woman has intermittent left flank pain after heavy water intake. Ultrasound shows left pelvicalyceal dilatation with normal calibre ureter. Diuretic (furosemide) DTPA renography is performed. Which finding on this study confirms significant pelviureteric junction obstruction?
- A Tracer retention in the pelvis with half-time of washout greater than 20 minutes after furosemide ✓
- B Prompt washout of the tracer from the pelvis within 5 minutes of furosemide
- C Bilateral symmetrical tracer excretion curves
- D Rapid cortical uptake phase with delayed vascular peak
Correct answer: A. Tracer retention in the pelvis with half-time of washout greater than 20 minutes after furosemide
Explanation
Diuretic renography is the standard functional test for PUJ obstruction. After furosemide, a normally draining pelvis washes out rapidly; a half-time of clearance longer than 20 minutes indicates significant obstruction, while 10 to 20 minutes is equivocal. Prompt washout (option B) argues against obstruction. The differential function it provides also guides whether dismembered pyeloplasty (Anderson-Hynes) is warranted versus observation.
Reference: Campbell-Walsh Urology, 12th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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