Figure 4c. Renal urinoma in a 39-year-old man who sustained right renal trauma from a stab wound. (a) Contrast-enhanced CT scan shows a fracture of the right kidney and a surrounding perinephric fluid collection (arrow). (b) On a contrast-enhanced CT scan obtained 7 days later, the perinephric fluid collection has increased in size and now demonstrates a high-attenuation rim. Percutaneous drainage of the presumed liquefied and infected hematoma was performed. (c) Sagittal US image obtained on the same day as b shows a fluid collection inferior to the right kidney. An 8-F drainage catheter was placed under US guidance. (d) Contrast-enhanced CT scan obtained 7 days after c shows a smaller but persistent perinephric fluid collection. High-volume catheter outputs persisted. Evaluation of the creatinine level of the fluid collection confirmed the diagnosis of urinoma. Antegrade ureteral stent placement was performed. Contrast material was injected through the percutaneous drainage catheter 5 days later due to decreased catheter output. (e) Pyelogram shows that the size of the urinoma cavity has decreased (arrow), but that communication between the percutaneous urinoma drainage catheter and the renal collecting system persists (arrowheads). (f) Contrast-enhanced CT scan obtained 10 days after e shows interval resolution of the perinephric urinoma. The combined use of the urinoma drainage catheter and ureteral stent promoted healing of the collecting system.