Conventional Urethrographic Imaging Evaluation: A Primer for Radiologists

Urethra is the terminal part of genitourinary tract with more complex anatomy in males compared to females. Urethra may be involved by various pathologies, namely, agenesis/atresia, abnormal external opening, valves, diverticulae, strictures, fistulas, duplications, dilatation, or neoplasms. Contrast urethrographic imaging studies, such as retrograde urethrography (RGU) and micturating cystourethrography (MCU), forms the initial mainstay investigation for the evaluation of anterior urethra, posterior urethra, and bladder, respectively. Assessment of stricture in terms of location, length, degree, postobstructive guides optimal management strategy. MCU in the preoperative phase shows obstructive changes in the bladder, and reflux and abrupt change in caliber of urethra while residual changes in the postoperative follow-up period. Urethral diverticulae can be congenital/acquired and is seen as bulbar/saccular contrast-filled outpouching, communicating with true urethral lumen. Urethrocutaneous fistulas are rare with urethral duplication being close differential in congenital ones. Megalourethra shows focal or fusiform dilatation of varying segments of the anterior urethra and has frequent associated anomalies which decides final outcome. Urethra calculi are uncommon and can be primary or secondary. This review article aims to describe common pathologies affecting the urethra and contrast urethrographic findings in them along with structured reporting checklist for both RGU and MCU for standardization and to provide consistent reporting lexicon.