A 46yo male patient has been in pain at his right lumbar region without fever for one month. He had a history of 10 year kidney stone but now no trouble with urination. Sometimes the pain is getting to the right flank. Ultrasound detect his right hydronephrosis with right kidney stones and the upper part dilated ureter which is obstructed by nothing. No stone in right ureter, and the urine jet on the right side weaker than the left one.
MSCT reveals a right hydronephrosis and the upper part of right tortous ureter in dilatation which is look like a fish hook. And the lower part of right ureter crepts posteriorly the inferior vena cava without in dilatation then continues going down to the urinary bladder. This is a circumcaval ureter which is blocked incompletly by the IVC, type low loop.
The patient went through an endoscopic surgery to repair the right ureter and remains well. In this case ultrasound has a limited role to detect a right hydronephrosis and hydroureter while MSCT could find out exactly pre-op the congenital malformation of right ureter.