Comparative diagnostic accuracy of sonourethrography and retrograde urethrography in anterior urethral strictures.

Abstract

Objective: To evaluate the diagnostic accuracy of retrograde urethrography and sonourethrography making cystourethroscopic findings as gold standard. Study Design: Cross-sectional Validation study. Setting: Department of Radiology and Urology, Gujranwala Teaching Hospital, Gujranwala. Period: April to October 2025. Methods: Over the course of six months (April to October 2025), fifty four patients with a clinical suspicion of anterior urethral strictures were enrolled in this cross sectional validation study and equally assigned to the RGU and SUG groups. Cystoscopy findings were used to compare diagnostic accuracy, sensitivity, specificity and stricture length. Results: Using intra-operative stricture length as the reference, sonourethrography (SUG) shows better diagnostic performance, with a sensitivity of 96.9%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 95.7%. Retrograde urethrography (RUG) showed a sensitivity of 93.8%, specificity of 95.5%, PPV of 96.8%, and NPV of 91.3%. Overall diagnostic accuracy was higher for SUG (98.1%) compared with RUG (94.4%). Conclusion: When evaluating anterior urethral strictures, SUG shows better assessment of stricture as compared to RGU in terms of diagnostic performance. As such, it should be used as an auxiliary or alternative imaging modality in clinical practice.