Sonographic diagnosis of urethral anomalies in infants: value of perineal sonography.

OBJECTIVE: To assess the value of urethral sonography including a perineal approach in evaluating urethral anomalies in infants. METHODS: A radiology database review identified 88 patients (mean age +/- SD, 64 +/- 84 days) who underwent voiding cystourethrography (VCUG) and urethral sonography as part of extended sonography of the urinary tract. Sonographic and VCUG images and reports were reviewed to assess agreement between both modalities for detection of urethral anomalies. RESULTS: Sonography facilitated the correct diagnosis of all 3 posterior urethral valves. The only urethral diverticulum, the only ectopic ureteric insertion into the urethra, the only urogenital sinus, and the only urethrovaginal fistula were also shown on sonography. In 73 (94%) of 78 cases, sonography correctly showed the absence of anomalies. In 5 infants, sonography could not reliably assess the urethra and showed indirect signs of urethral anomalies; however, these patients had normal urethras on VCUG. CONCLUSIONS: Our data show that sonography of the urethra is a valuable tool for diagnosis of urethral anomalies. Especially, negative findings on sonography are highly suggestive of the absence of urethral anomalies. Positive or equivocal sonographic findings should indicate VCUG.