Voiding urosonography with ultrasonography contrast medium in children

Voiding urosonography (VUS) with ultrasonography contrast medium is a new modality in the detection of vesicoureteral reflux (VUR) in children. The purpose of this study was to evaluate the diagnostic accuracy of VUS compared with voiding cystourethrography (VCUG) in the detection of VUR. One hundred and eighteen patients, aged 3 weeks to 16 years, with 234 ureterorenal units, were investigated by VUS with ultrasonography contrast medium and radiographic VCUG in one session. The indications were predominantly urinary tract infection and follow-up of previously detected VUR. During the sonographic examination, the bladder was filled with saline solution and an ultrasonography contrast medium (Levovist) was administered through a catheter. Reflux was diagnosed when echogenic bubbles were observed in the ureter or in the renal pelvis. Afterwards, conventional VCUG was performed. Concordant findings were obtained in 210 of 224 ureterorenal units (93.7%). Reflux was excluded by both methods in 174 units (77.7%). With the VCUG as the reference, the sensitivity of VUS was 90%, the specificity 94.6%, the positive predictive value 78.3%, and the negative predictive value 97.8%. The accuracy was 93.7%. In conclusion, VUS with ultrasonography contrast medium is a reliable diagnostic tool for the detection of VUR in children.