PURPOSE: To determine normal postoperative CT findings and tumor recurrence in patients who have under-goneradical cystectomy and urinary diversion. MATERIALS AND METHODS: We retrospectively reviewed the postoperative CTscans of 51 patients who had un-dergone radical cystectomy with urinary diversion, and in analysis speciallyemphasised normal postoperative CT findings and recurrent cancer in the surgical bed. Among these 51 patients, 43had undergone incontinent urinary diversion(Bricker operation), while for six, diversion had been continent (Kockprocedure). Attempts were also made to characterise the CT findings of each procedure according to the location ofthe ileal pouch, the pattern of contrast collection within the pouch, and the morphology of the ileocutaneostomysite. RESULTS: Each urinary diversion procedure demonstrated characteristic postoperative CT appearances. TheBricker procedure revealed a contrast-filled ileal conduit in the right lower quadrant excreting into theileocu-taneostomy site, while the Kock procedure demonstrated layering of contrast and urine within the pouch aswell as artificially intussuscepted afferent and efferent ileal loops at the anastomotic sites. Thirty-three smallsoft tissue density lesions in the surgical bed were seen in 19 patients (37%). Thirty one were bilateral (n=28)or unilateral (n=3) triangular or oval shaped soft-tissue-density lesions and two were unilateral irregular shapedlesions. Follow-up CT scans showed that all triangular or oval-shaped lesions were smaller (n=8) or show no changein size (n=23) ; they were thought to represent postoperative fibrosis or granulation tissue. Two cases ofirregular-shaped soft-tissue-density lesions were seen on follow-up CT scans to be larger, and these wereconfirmed by percutaneous biopsy to be recurrent cancer. CONCLUSION: It is important for the radiologist to befamiliar with normal postoperative CT findings of various urinary diversion procedures as well as to recognize arelatively high incidence (37%) of small soft tissue den-sity lesions in a surgical bed. In our study, smalltriangular or oval-shaped soft-tissue-density lesions in the sur-gical bed (especially when these were bilateral)were thought to represent postoperative fibrosis or granulation tissue, and close follow-up by means of CTscanning rather than an invasive procedure is therefore warranted.