Comparison of contrast-enhanced voiding urosonography with voiding cystourethrography in pediatric vesicoureteral reflux

Objective: Voiding cystourethrography (VCUG) has been considered as the gold standard technique for the diagnosis of vesicoureteral reflux (VUR). But, it requires fluoroscopic guidance which expose children to radiation. Voiding urosonography (VUS) is technically analogous to VCUG and has the major advantage of zero radiation exposure. This study aims to determine the efficacy of contrast enhanced-VUS (ce-VUS) with respect to VCUG in diagnosing VUR. Material and methods: This study involves 30 children over a period of 3 years. All patients underwent a VCUG followed by the ce-VUS on the same day. All VUS studies were done by the same sonologist in the sonography department. The images were recorded and reviewed by the same sonologist before reporting. Results: The median age of the patients was 51.53 months. There were 21 males and 9 females. On VCUG, 16 patients had no reflux, and 14 patients had reflux. On ce-VUS, 14 patients had no VUR, and 16 patients had VUR. Of the total 58 kidney-ureter units (KUUs), VUR was detected in 17 KUUs on VCUG and in 21 KUUs on ce-VUS. Thus, ce-VUS detected 4 refluxing units that were not seen on VCUG. In right KUUs, ce-VUS detected VUR in 3 units where no reflux was found in VCUG. In the 28 left KUUs, 25 units on ce-VUS showed concordance with the grade of VUR as detected by VCUG; 3 were discordant. Two units on ce-VUS showed a VUR one grade higher than the corresponding grade on VCUG and in one unit it was one grade lower. Thus, in total, ce-VUS picked up 4 cases which were missed by VCUG. Conclusion: ce-VUS is a good imaging modality when compared to voiding cystourethrography to assess pediatric vesicoureteral reflux, in view of its superior diagnostic performance, feasibility and radiation safety for children.