CT
The CT images demonstrate a horseshoe kidney with a moderate left nephrohydroureter due to small stone (5 mm) impacted at the vesicoureteric junction. A retroperitoneal fluid collection is noted in the perirenal space and along the left psoas muscle corresponding to a urinoma as confirmed on the excretory phase. The contrast extravasation from the urinary tract (renal pelvis) is well visualized on the excretory phase. Note a small simple renal cyst.