Renal Transplant Hydronephrosis

Imaging

• Dilated renal pelvis and calyces ± dilated ureter

• Distended bladder may cause functional obstruction or reflux resulting in hydronephrosis

• Low-level echoes within lumen suggest pus (pyonephrosis) or blood (hemonephrosis)

• Highly echogenic shadowing intraluminal structures represent stones, twinkling artifact on color Doppler

• Urothelial thickening suggests infection or rejection

• Ultrasound is sensitive and specific for hydronephrosis but may be limited for site of obstruction