3. Male urethra injection urethrogram, oblique projection

This study was performed by inserting the tip of a urinary (Foley) catheter into the urethral meatus and inflating the catheter‰s balloon with air, to anchor it in the fossa navicularis. Water-soluble contrast was then injected into the urethra to fill it in a retrograde manner.

During this study there was some reflux of contrast into the prostatic glands via the prostatic ductules. The membranous portion is the shortest; it passes through the pelvic floor and is encircled by the external urethral sphincter which is usually contracted, except when voiding (urinating). Note how narrow the lumen of the membranous urethra is; it would be better distended and visualized when the external sphincter relaxes during an anterograde (voiding) urethrogram. The spongy urethra passes through the corpus spongiosum of the penis. The lacunae are where the ducts of the urethral glands drain into the urethra.