RADIOLOGY: GENITOURINARY: GU: Case# 32918: RUPTURED BLADDER SECONDARY TO GUNSHOT WOUND. 22 year old male status post gunshot wound to the left pelvis. We are requested to evaluate for position of the bullet as well as for bladder injury. Patient has gross hematuria. Initial images demonstrate metallic slug lying immediately medial to the anterior aspect of the acetabulum. There is some mild mass effect upon the bladder in this region without obvious hematoma. The bullet is in close proximity to the iliac vessels. The iliac artery appears unaffected although the vein is somewhat poorly delineated in the inguinal region. The ureters are well delineated and appear unremarkable on all series. Soft tissues of the left inguinal region and extraperitoneal spaces. Inspection of bone windows reveals the bullet fragment to abut the bone but no fractures are identified. Cystogram reveals extraperitoneal extravasation of contrast on post-void images which is most pronounced at the bladder base extending predominantly to the left of the bladder in the area of the bullet and along the extraperitoneal space below the rectus muscles. No intraperitoneal extravasation is seen. A Foley catheter is present within the bladder lumen. Bladder rupture occurs in 10% of patients with pelvic fractures usually due to lacerations by bone fragments resulting in leakage of urine and contrast into the extraperitoneal space. Intraperitoneal rupture is usually the result of blows to the lower abdomen while the bladder is distended. Both types of rupture are readily demonstrated by CT following contrast administered intravenously or by bladder catheter. With intraperitoneal ruptures, contrast is seen within the peritoneal cavity surrounding bowel loops and extending into the pericolic gutters. Extraperitoneal rupture results in leakage of urine and contrast into the retropubic space and extending along fascial planes to the abdominal wall, into the retroperitoneal compartments, and into the scrotum and thigh.