CT cystography in the evaluation of major bladder trauma.

Computed tomographic (CT) cystography has been advocated in lieu of conventional cystography in the initial work-up of patients with suspected urinary bladder trauma. CT cystography was applied to a classification scheme for bladder injury based on the degree of wall injury and anatomic location and demonstrated characteristic imaging features for each type of injury. In bladder contusion (type 1), findings are normal. In intraperitoneal rupture (type 2), CT cystography demonstrates intraperitoneal contrast material around bowel loops, between mesenteric folds, and in the paracolic gutters. Manifestations of interstitial injury (type 3) include intramural hemorrhage and submucosal extravasation of contrast material without transmural extension. In extraperitoneal rupture (type 4), the path of extravasated contrast material is variable: Extravasation is confined to the perivesical space in simple extraperitoneal ruptures, whereas in complex extraperitoneal ruptures, contrast material extends beyond the perivesical space and may dissect into a variety of fascial planes and spaces. Combined intra- and extraperitoneal rupture (type 5) usually demonstrates extravasation patterns that are typical for both types of injury. Familiarity with these CT cystographic features allows accurate classification of bladder injury and allows prompt, effective treatment with less radiation exposure than and without the added cost of conventional cystography.