Contrast-enhanced sonographic detection of vesicoureteral reflux in children: comparison with voiding cystourethrography.

PURPOSE: Prospective evaluation of contrast-enhanced sonography (CES) as an alternative to radiographic voiding cystourethrography (VCUG) in the detection of vesicoureteral reflux (VUR).

MATERIALS AND METHODS: Seventy-six children (age range: 0 - 9 years, mean age 1.4 years) with suspicion of VUR due to various indications were examined by contrast-enhanced sonography (CES) and VCUG. CES examination was performed after instillation of Levovist into the catheterized urinary bladder, which had been prefilled with normal saline. Reflux was diagnosed when hyperechogenic microbubbles were observed in the renal units. Thereafter, VCUG was performed in all patients through the same catheter. CES findings were compared to the results of VCUG.

RESULTS: CES showed VUR in 24 renal units whereas VCUG showed reflux in 18 renal units. With regard to the presence of VUR, the findings obtained by both methods were concordant in 17 renal units. Taking VCUG as the reference standard, the sensitivity of CES was 96 %, the specificity was 94.8 %, the positive predictive value 77.4 % and the negative predictive value 99.2 %. Additionally, McNemar test showed that CES detected a statistically significant higher number of renal units with VUR (p < 0.05).

CONCLUSION: It is suggested that CES is an accurate and reliable imaging modality for the detection of VUR, although it cannot replace VCUG in some cases. In addition, CES can be recommended in the follow-up of VUR, reducing the number of radiographic investigations.