Detection of crossing vessels in pediatric ureteropelvic junction obstruction: Clinical patterns and imaging findings

This study confirms the need to maintain a high index of suspicion for the presence of a CRV when intervening in a clinically symptomatic older child, although 25% of infants with antenatally detected UPJO did have one too. Our subset analysis demonstrated that MRU is a reliable method of detecting crossing vessels.270Figure. (A) Normal bilateral renal arteries (arrows) on post-contrast T1-weighted fat-saturated scan. On the left side there is ureteropelvic junction obstruction and clearly the left renal artery enters into the kidney above the dilated renal pelvis. (B) Left crossing vessel detected on post-contrast T1-weighted fat-saturated scan (thin arrow) without additional signs of obstruction on fMRU (not shown) and, no crossing found intraoperatively. (C) A post-contrast T1-weighted fat-saturated scan demonstrating a right crossing vessel (arrow) arising as a branch from the main renal artery and wrapping around the dilated renal pelvis to enter the kidney at the ureteropelvic junction. (D) Obstruction of the proximal ureter is noted (arrow) on the non-contrast 3D T2-weighted fat-saturated scan. The obstructing right crossing vessel was identified intraoperatively. (E) Sensitivity and specificity of fMRU for identification of the presence of crossing renal vessels and for ureteral obstruction.