What is the diagnostic study of choice for suspected urethral injury?

• A. MRI pelvis
• B. CT cystography
• C. Ultrasound of perineum
• D. Retrograde urethrography

Answer: (D)

When urethral injury is suspected, retrograde urethrography is the best test because it directly images the urethral lumen to show whether there is a disruption, its location (anterior vs posterior), and the extent of injury. This information is crucial for management, since seeing a rupture alerts you to avoid attempting catheterization and to plan alternative drainage (often suprapubic) rather than forcing a urethral catheter, which could worsen a rupture or create a false passage.

Other imaging options have limited usefulness for assessing urethral integrity. MRI pelvis isn’t practical acutely and isn’t the standard test to confirm urethral disruption. CT cystography mainly evaluates bladder injury and may miss isolated urethral injuries. Ultrasound of the perineum is not reliable for detailing urethral disruption. Retrograde urethrography specifically targets the urethral lumen and is therefore the diagnostic study of choice.