Imaging description

A urethral diverticulum is a variably sized outpouching of the urethra. The condition occurs primarily in middle-aged and elderly women, in whom it is thought to arise from rupture or dilatation secondary to infection or obstruction of normal paraurethral glands. Urethral diverticula appear at ultrasound, CT, or MRI as fluid-filled cyst-like structures wrapped around the urethra and protruding into the anterior vaginal wall (Figures 89.1 and 89.2). Urethral diverticula may be seen during voiding cystourethrogram (Figure 89.3), but only if they fill with contrast. If strongly suspected clinically, special techniques to generate high pressure in the urethra may help drive contrast into the diverticulum. This can be achieved by occluding the meatal opening with a finger during voiding, or by using a special double-balloon catheter technique that effectively seals the urethra at both ends and forces contrast into the diverticulum from a hole in the catheter between the balloons (Figure 89.4). In a study of 32 women with symptoms of a urethral diverticulum and using surgery as the gold standard, the sensitivity of double-balloon urethrography was 100% compared to 44% for standard voiding cystourethrography [1]. Transvaginal ultrasound and endovaginal MRI are more advanced techniques that can also be used when standard imaging has failed to demonstrate a suspected diverticulum [2–4].