CT cystography: Radiographic and clinical predictors of bladder rupture

OBJECTIVE. Our goal was to identify radiographic and clinical variables tha t correlate with bladder rupture that may then be used as selection criteri a for CT cystography in trauma patients. SUBJECTS AND METHODS, Hemodynamically stable trauma patients with hematuria were examined under standardized protocol with dynamic oral and IV contras t-enhanced CT of the abdomen and pelvis, followed immediately by CT cystogr aphy CT cystography consisted of contiguous 5-mm axial scans of the pelvis after retrograde distention of bladder with 300-400 ml of 4% iodinated cont rast material, Radiographic and clinical variables (pelvic fracture, pelvic fluid, intraabdominal visceral injury, degree of hematuria, hematocrit, un its of blood transfused, base deficit, injury mechanism, seat belt use, sex , age) were assessed and statistically analyzed using the two-tailed Fisher 's exact test and Wilcoxon's rank sum test. Positive and negative individua l and multivariate predictors were analyzed. RESULTS. Of the 157 patients entered in our study, 12 (eight males and four females) had bladder rupture. One or more pelvic fractures were present in nine (75%) of the 12 patients (p < 0.001). Pubic symphysis diastasis, sacr oiliac diastasis, and sacral, iliac, and pubic rami fractures were statisti cally associated with bladder rupture. Isolated acetabular fractures did no t correlate with rupture, Eight (67%) of the 12 patients with bladder ruptu re revealed on CT cystography had gross hematuria (p < 0.001). No ruptures were seen in patients with <25 RBC/HPF (red blood cells per high-power fiel d). All patients with rupture had pelvic fluid revealed on standard contras t-enhanced CT (p < 0.001). CONCLUSION, Gross hematuria, pelvic fluid, and specific pelvic fractures we re highly correlated with bladder rupture; identification of these findings may help in selection of trauma patients for CT cystography.