Contrast material in posterior vaginal fornix mimicking bladder rupture: CT features

Abdominopelvic CT of a 22-year-old woman who sustained blunt abdominal trauma revealed a collection of contrast material posterior to the bladder. This CT appearance was interpreted as evidence of bladder rupture, despite previously performed normal retrograde cystography. Subsequent urologic studies confirmed the absence of bladder injury. Retrospective review of CT revealed that collection was within the vagina. This case demonstrates an important false-positive CT diagnosis of bladder rupture and confirms the importance of retrograde cystography for the diagnosis of bladder rupture.