The role of urethrography in urethral disease. Part I. Accurate radiological localization of the membranous urethra and distal sphincters in normal male subjects.

Radiological localization of the membranous urethra requires visualization of the whole urethra with dynamic retrograde urethrography and voiding cystourethrography. These methods are described together with a critical analysis of other methods of urethrographic examination, that is static retrograde urethrography alone and voiding urethrography alone. The normal radiological landmarks allowing accurate localization of the membranous urethra are described and correlated with anatomical dissections from 9 autopsy specimens.