Urethra retrograde urethrography

Stenoses due to pelvic fracturing, on the other hand, affect almost exclusively the membranous urethra. They can be easily investigated with retrograde urethrography and voiding cystourethrography, but are difficult to explore with sonourethrography. 

Retrograde urethrography is the best way to study fistulae located under the striate sphincter of the urethra since it can visualize the fistula, the concomitant cavities and passage of the contrast agent into adjacent organs. 

Retrograde urethrography is rarely indicated, and retrograde or suprapubic VCU should be preferred in most patients. Such an examination is usually performed to rule out a ruptured urethra in an adolescent. A Foley catheter is inserted in the distal urethra. The balloon is then inflated in the fossa navicularis, and the urethra is slowly and retro-gradely injected. Lateral and oblique pictures are taken. In most instances, the posterior urethra is not opacified. This should not be considered abnormal. 

Fig. 25.15. Complete disruption of the membranous urethra in an adolescent boy shown by retrograde urethrography (arrow). Note the inflated balloon of the Foley catheter in the fossa navicularis...

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