Clinical Scenario:
A 2-year-old boy is evaluated after recurrent febrile urinary tract infections. A micturating cystourethrogram (MCUG) demonstrates reflux of contrast from the bladder into the ureter and renal pelvis. The ureter is mildly dilated, but there is no obvious blunting of the renal calyces. The renal pelvis is not significantly dilated, and the calyceal fornices remain sharp.
Which grade of vesicoureteric reflux (VUR) is most consistent with these findings?
A. Grade I
B. Grade II
C. Grade III
D. Grade IV
E. Grade V
Correct answer & Explanation:
Correct answer: C. Grade III
Explanation
This is Grade III VUR.
The key is to assess how far the contrast travels and the degree of dilatation/distortion of the ureter and collecting system.
How to grade VUR — International Reflux Study classification
| Grade | Key MCUG finding |
|---|---|
| I | Reflux confined to the ureter |
| II | Reflux reaches the renal pelvis and calyces, but without dilatation |
| III | Mild–moderate dilatation of the ureter, renal pelvis and calyces, with minimal or no blunting of the calyces |
| IV | Moderate dilatation/tortuosity of the ureter and collecting system with blunting of the calyces, but papillary impressions are generally preserved |
| V | Gross dilatation and tortuosity of the ureter with marked dilatation of the collecting system and loss of papillary impressions |
The scenario describes reflux reaching the renal pelvis and calyces with mild ureteric/collecting-system dilatation but no significant calyceal blunting, making Grade III the best answer.
Why the other options are wrong
- Grade I: Reflux would remain confined to the ureter and would not reach the renal pelvis.
- Grade II: The contrast reaches the renal pelvis and calyces, but there should be no dilatation.
- Grade IV: There would be more pronounced dilatation and calyceal blunting.
- Grade V: This represents severe reflux with gross ureteric tortuosity and dilatation and loss of papillary impressions.
🧠 CPSP Exam Trick
Remember the progression:
I → ureter only
II → pelvis + calyces, no dilatation
III → dilatation begins, minimal calyceal blunting
IV → dilatation + tortuosity + calyceal blunting
V → gross tortuosity/dilatation + loss of papillary impressions
Reference: International Reflux Study Committee classification of primary VUR; American Urological Association guideline on vesicoureteral reflux in children. AUA Vesicoureteral Reflux Guideline
