Which radiographic test is used to evaluate urethral injury?

Which radiographic test is used to evaluate urethral injury?

• A. Retrograde urethrogram
• B. Renal ultrasound
• C. CT scan abdomen
• D. MRI pelvis

Answer: (A)

Evaluating suspected urethral injury requires imaging that directly visualizes the urethral lumen. A retrograde urethrogram accomplishes this by injecting contrast into the distal urethra and taking radiographs as the contrast travels toward the bladder. If the urethra is intact, the contrast outlines a continuous path into the bladder; if there is a tear, contrast extravasates at the injury site and the disruption becomes visible. This test clearly shows whether an injury is present and where it is, guiding decisions about catheterization or urinary diversion. In trauma, avoid blind catheterization before imaging because it can worsen a urethral tear. Renal ultrasound looks at kidneys and the collecting system, not the urethra. A CT scan of the abdomen helps assess pelvic fractures and other intra-abdominal injuries but does not reliably define urethral continuity unless a dedicated CT urethrogram is performed, which isn’t the standard initial test for urethral injury. MRI of the pelvis provides detailed soft tissue imaging but isn’t practical for acute urethral injury assessment due to time and availability. Therefore, the retrograde urethrogram is the best tool for evaluating urethral injury.

Evaluating suspected urethral injury requires imaging that directly visualizes the urethral lumen. A retrograde urethrogram accomplishes this by injecting contrast into the distal urethra and taking radiographs as the contrast travels toward the bladder. If the urethra is intact, the contrast outlines a continuous path into the bladder; if there is a tear, contrast extravasates at the injury site and the disruption becomes visible. This test clearly shows whether an injury is present and where it is, guiding decisions about catheterization or urinary diversion. In trauma, avoid blind catheterization before imaging because it can worsen a urethral tear.

Renal ultrasound looks at kidneys and the collecting system, not the urethra. A CT scan of the abdomen helps assess pelvic fractures and other intra-abdominal injuries but does not reliably define urethral continuity unless a dedicated CT urethrogram is performed, which isn’t the standard initial test for urethral injury. MRI of the pelvis provides detailed soft tissue imaging but isn’t practical for acute urethral injury assessment due to time and availability. Therefore, the retrograde urethrogram is the best tool for evaluating urethral injury.