Contrast-enhanced sonography of vesicoureterorenal reflux in children: preliminary results.

OBJECTIVE: The aim of our study was to evaluate contrast-enhanced sonography as an alternative to radiographic voiding cystourethrography in the detection of vesicoureteral reflux. SUBJECTS AND METHODS: A total of 46 children, ranging in age from 3 weeks to 14 years (median: 4 years, 6 months) with 92 ureterorenal units were investigated for reflux using radiographic voiding cystourethrography and contrast-enhanced sonography in one session. After sonography of the urinary tract, the bladder was filled with saline solution via a catheter. Later, a contrast-enhancing agent was instilled and sonography was repeated. Documentation was done using S-VHS video and a laser camera. Reflux was diagnosed when microbubbles were observed in the ureter or in the renal pelvis. In addition, conventional voiding cystourethrography was performed. Patients without micturition during either sonography or radiographic examination were excluded (eight ureterorenal units). RESULTS: The findings obtained by contrast-enhanced sonography and voiding cystourethrography were concordant in 78 ureterorenal units (92.9%). No reflux was detected in 67 units (79.8%) by either method. With voiding cystourethrography as the standard of reference, the sensitivity of contrast-enhanced sonography was 91.7%; the specificity, 93.1%; and the accuracy, 92.9%. The positive predictive value was 68.8%, and the negative predictive value was 98.5%. CONCLUSION: Contrast-enhanced sonography is highly sensitive for the detection of vesicoureteral reflux. Therefore, it may reduce the number of radiographic investigations.