<b>Diagnostic Accuracy of Retrograde Urethrogram in Diagnosing Urethral Stricture Keeping Urethroscopy / Surgical Findings as Gold Standard</b>

Background: Urethral stricture is a clinically important cause of lower urinary tract obstruction in males and may lead to dysuria, weak urinary stream, urinary retention, recurrent infection, and impaired quality of life if diagnosis is delayed. Retrograde urethrography is widely used as an initial imaging investigation because it is accessible, inexpensive, and provides anatomical information about the urethral lumen, but its diagnostic performance should be evaluated against direct reference-standard findings. Objective: To determine the diagnostic accuracy of retrograde urethrography for detecting urethral stricture in symptomatic male patients, using urethroscopy or intraoperative surgical findings as the reference standard. Methods: This cross-sectional diagnostic accuracy study was conducted in the Department of Radiology, Liaquat National Hospital, Karachi, from January 2024 to June 2024. A total of 210 male patients aged 15–65 years with clinical suspicion of urethral stricture underwent retrograde urethrography, followed by comparison with urethroscopy or surgical findings. Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were calculated from a two-by-two diagnostic table. Results: Reference-standard confirmed urethral stricture was present in 117 patients (55.7%). Retrograde urethrography showed 113 true-positive, 90 true-negative, 3 false-positive, and 4 false-negative findings. Sensitivity was 96.6%, specificity 96.8%, positive predictive value 97.4%, negative predictive value 95.7%, and overall accuracy 96.7%. Bulbar urethra was the most frequent stricture site, observed in 124 patients (59.0%). Conclusion: Retrograde urethrography demonstrated high diagnostic accuracy for detecting urethral stricture and is a dependable first-line imaging modality for symptomatic male patients in tertiary-care practice.