Contrast ultrasound of the urethra in children.

The aim of this study was to report our experience with transperineal ultrasound in studying the urethra, as a complementary technique to contrast-enhanced voiding urosonography (VUS). The VUS was performed in 350 patients (244 males, 106 females) less than 4 years of age, and complemented with perineal US. Ultrasound of the kidneys and bladder was obtained before and during bladder filling and post-voiding. The urethra and the neck of the bladder were evaluated sagittally by transperineal ultrasound (5-7.5 MHz) before, during, and after voiding. Only cases of posterior urethral valves diagnosed at VUS were followed by voiding cystourethrography (VCUG), which was performed on a different day. A satisfactory evaluation of the urethra was obtained in 332 cases (94.86%): (a). normal urethra ( n=328); and (b). posterior urethral valves ( n=4). In the latter 4 cases there was concordance between results at VUS and VCUG. Eighteen cases (5.14%) were excluded from the study because the quality of the examination was suboptimal. Transperineal US offers an initial imaging modality for studying urethral pathology and thus may complement VUS.