Fig. 1

A 79-year-old woman complaining of hypogastric pain, dysuria and fecaluria. Cystoscopy did not identify fistulous orifices. Abdomino-pelvic CT showed sigmoid diverticulosis with mild signs of perivisceral and fascial inflammation, focally adherent to the thickened left bladder wall (a). Some air in the bladder lumen without previous catheterization suggested a probable colovesical fistula, which was not directly visualized during excretory phase acquisition (focused sagittal MIP image in b). At MDCT cystography, significant leakage of diluted contrast agent in the sigmoid colon was observed through a short fistula, effectively depicted (arrowheads) on axial (c) and oblique-coronal reformatted (d) images. Elective surgery included segmental resection of the sigmoid colon, resection and repair of the bladder dome