Clinical scenario: UTI | Vesicoureteral reflux | Long term follow up
A 7-year-old girl has had multiple febrile urinary tract infections since infancy despite appropriate treatment. She is normotensive and her serum creatinine is normal. A micturating cystourethrogram (MCUG) confirms Grade IV vesicoureteral reflux. A DMSA scan shows upper pole cortical scarring of the right kidney.
Which investigation is most useful for long-term follow-up of renal damage?
A. DMSA scan
B. Intravenous urography
C. MAG-3 renogram
D. Renal ultrasound
E. Voiding cystourethrogram
Correct answer & Explanation:
Correct answer: A. DMSA scan
Explanation:
The DMSA renal scan is the gold standard for detecting and monitoring renal cortical scarring caused by reflux nephropathy.
- DMSA scan → Best for cortical scars and differential cortical function.
- MAG-3 renogram → Assesses renal drainage and split renal function, mainly in obstructive uropathy.
- MCUG (VCUG) → Diagnoses and grades vesicoureteral reflux but does not assess renal scarring.
- Ultrasound → Detects hydronephrosis and renal size but is relatively insensitive for cortical scars.
- Intravenous urography → Largely obsolete in pediatric practice.
Learning Point
Investigation of choice:
- Vesicoureteral reflux → MCUG
- Renal cortical scarring (reflux nephropathy) → DMSA scan
- PUJ obstruction → MAG-3 renogram
