RETROGRADE URETHROGRAPHY AND MAGNETIC RESONANCE URETHROGRAPHY IN THE ASSESSMENT OF MALE URETHRAL STRICTURE DISEASE: A CROSS-SECTIONAL DIAGNOSTIC STUDY

Abstract

Background: Male urethral stricture is a prevalent urological disorder with considerable morbidity. Effective imaging is of paramount importance in both diagnosis and surgical planning. Retrograde Urethrography (RUG) remains the standard imaging technique, while Magnetic Resonance Urethrography (MRU) provides a non-invasive alternative with precise anatomical assessment.

Objective: To compare the clinical usefulness of Retrograde Urethrography and Magnetic Resonance Urethrography in the assessment of male urethral stricture disease, with special reference to their value in surgical planning.

Materials and Methods: In this prospective cross-sectional diagnostic study, 30 male patients (mean age 42.7 ± SD) clinically suspected of urethral stricture at Kilpauk Medical College and Government Rajaji Hospital (April 2012–February 2013) underwent RUG followed by contrast-enhanced MRU. Inclusion criteria comprised all adult males with suspected urethral stricture; exclusions included acute urethritis, prior urethroplasty or internal urethrotomy, MRI contraindications, or pelvic floor distraction defects. Imaging findings (site, number, length of strictures, spongiofibrosis, associated pathology, and prostatic displacement) were correlated with endoscopic or surgical findings. Mean stricture lengths and diagnostic accuracy—including sensitivity, specificity, predictive values, and kappa agreement—were calculated. Paired t-tests and correlation analyses assessed measurement concordance between RUG/MRU and surgical findings.

Results: Thirty patients (24 anterior, 6 posterior strictures) were included. Mean overall stricture lengths determined by RUG, MRU, and surgery were 1.72 cm, 1.56 cm, and 1.56 cm, respectively. In anterior strictures, MRU measurements (1.36 cm) correlated more closely with surgical length (1.29 cm; r=0.833) than RUG (1.19 cm; r=0.530). In posterior strictures, MRU (2.55 cm; r=0.924) matched surgical findings (2.50 cm) more accurately than RUG (4.08 cm; r=0.491). Overall diagnostic accuracy for predicting surgery type reached 90.1% for MRU versus 83.3% for RUG. RUG demonstrated 80% sensitivity and 85% specificity, with a kappa of 0.634 for length-based surgical planning.

Conclusion: MR urethrography is a superior non-invasive modality compared to RUG for assessing male urethral stricture, particularly regarding accurate stricture length, evaluation of spongiofibrosis, and delineation of posterior distraction defects, thereby enhancing preoperative planning.