Fig. 3.

Six-month-old with history of febrile UTI. Initial ultrasound showed moderate to severe right hydronephrosis and megaureter. VCUG showed grade 3 left-sided reflux, no right reflux, and bilateral periureteral diverticula. Together with the MRU findings, this patient was diagnosed with refluxing, obstructive congenital primary megaureter. a Coronal maximum intensity projection (MIP) image from a 3D T2-weighted sequence shows marked right pelvocaliectasis and a dilated, tortuous right ureter. A bladder catheter is in place with a fluid-filled balloon in the bladder lumen. b Coronal T2-weighted single-shot fat suppressed image shows abrupt narrowing and “beaking” of the distal ureter at the ureterovesical junction consistent with obstruction. c Single image from the dynamic post-contrast sequence shows diffuse parenchymal thinning of the right kidney with delayed excretion into the renal collecting system relative to the left, indicative of clinically relevant obstruction