Utility of routine trauma CT in the detection of bladder rupture

Rationale and Objectives. The purpose of this study was to determine the fr equency with which routine computed tomography (CT) fails to depict bladder rupture, the potential utility of delayed CT scans, and whether these find ings might be useful in determining which patients may require subsequent c ystography. Materials and Methods. Cystograms and abdominal and pelvic CT scans of 54 p atients with blunt trauma and in whom bladder rupture was clinically suspec ted were retrospectively reviewed. Blind readings of CT scans were performe d by two genitourinary radiologists. Cystograms were used as the standard. Results. Cystograms depicted bladder rupture in 10 patients. On CT scans, e xtravesical fluid was depicted in all three patients with intraperitoneal b ladder rupture (although only a small amount of pelvic intraperitoneal flui d was present in two of these patients), in all seven patients with extrape ritoneal bladder rupture, and in 32 of the 44 patients without bladder inju ry. Contrast material had been excreted into the bladder at the time of the initial or delayed CT in eight patients with bladder rupture; however, ext ravasation was identified in only four of the eight. In two of the four pat ients without extravasation, the bladder was distended at the time of CT. N o bladder injuries were found in the 12 patients in whom pelvic fluid was n ot identified on CT scans. Conclusion. The absence of pelvic fluid on a trauma CT scan indicates that bladder rupture is unlikely. Even when a partially opacified bladder is pas sively distended, bladder injury may be present despite the absence of cont rast material extravasation.