- Etiology: intrinsic narrowing of ureter or extrinsic compression of ureter from a crossing blood vessel
- Imaging: extremely dilated renal collecting system without seeing a dilated ureter
- Clinical: hydronephrosis is most common cause of a renal mass in a neonate and ureteropelvic junction obstruction is the most common cause of hydronephrosis, can present as flank pain in teen after large fluid challenge or as large renal injury after minor blunt abdominal trauma
Radiology Cases of Ureteropelvic Junction Obstruction


