E2364. Traumatic Bladder Rupture: Utility of CT Cystogram and Clinical Implications
  1. Frederick Moh; Keck Medical Center at University of Southern California
  2. Armonde Baghdanian; Keck Medical Center at University of Southern California
  3. Arthur Baghdanian; Keck Medical Center at University of Southern California
Blunt or penetrating abdominopelvic trauma may result in bladder rupture, which can be overlooked on abdominopelvic computed tomography (CT) scans, leading to delayed diagnosis and increased morbidity. Timely acquirement of a CT cystogram and correct technique can aid in accurate early diagnosis. CT cystography can be used to characterize and classify bladder injury and aid in clinical management decisions. The purpose of this exhibit is to illustrate pelvic anatomy, discuss important technique points, review the bladder rupture classification system, and demonstrate pitfalls to avoid missed diagnosis.

Educational Goals / Teaching Points
Illustrate pelvic anatomy. Review the classification of bladder rupture on CT cystography. Understand when to suspect bladder rupture to recommend CT cystography. Explain the clinical implications of a missed diagnosis. Review pitfalls in bladder trauma diagnosis.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Anatomy: Bladder enters the pelvis from the abdomen at around age of 6. In adults, bladder is almost within the lower pelvis. Space of Retzius, between the pubic symphysis and anterior bladder, is common for contrast to pool in extraperitoneal rupture from pubic bone fracture. In men, rectovesical fascia separates the posterior bladder from rectum. In women, posterior peritoneal reflection is the vesicouterine pouch. Bladder dome rupture, abutting the peritoneal lining, can cause intraperitoneal contrast pooling. The bladder neck is held by ligaments, puboprostatic ligaments in male and pubovesical ligaments in female, within the pelvis and the pelvic fascia. Violation of fascial planes can cause contrast to leak into the perineum, scrotum, abdominal wall or lower extremities. Technique: 400 cc of Isovue 370 is instilled via Foley catheter into the bladder, only after excluding urethral injury. Multiplanar reformats must be performed. CT cystography may be performed during delayed phase of CT ordered for pelvic trauma to reduce radiation dosing. Findings: Type 1 urinary bladder rupture indicates contusion without leakage. Type 2 is intraperitoneal rupture. Type 3 represents interstitial injury with contrast extending into but not beyond wall. Type 4 is extraperitoneal rupture which is classified into simple or complex when contrast extends beyond extraperitoneal pelvis. Type 5 reflects combined intraperitoneal and extraperitoneal injury. Pitfalls: Bladder diverticula can be misdiagnosed as perforation. Pelvic hematoma or large rupture can cause incomplete bladder distention leading to missed rupture. Bladder rupture can be misdiagnosed as urethral injury when contrast extravasation is seen in the penis. Multiplanar reformats are needed for bladder dome lacerations.

CT cystography should be considered in blunt or penetrating abdominopelvic trauma. Pelvic fractures increase the risk of bladder rupture. Appropriate CT cystography technique is important for accurate diagnosis. Knowledge of bladder and pelvic anatomy will allow understanding of the path of contrast leakage. Distinguishing intraperitoneal from extraperitoneal bladder rupture can aid appropriate clinical management.