Contrast-enhanced Voiding Urosonography with Second-generation Ultrasound Contrast Agent versus Micturating Cystourethrogram for Diagnosis of Vesicoureteric Reflux

Objective: To review the performance of contrast-enhanced voiding urosonography (ceVUS) and micturating cystourethrogram (MCU) in diagnosing vesicoureteric reflux (VUR), and to evaluate the safety profile of ceVUS and the relevant imaging findings. Methods: We retrospectively reviewed all patients who underwent both ceVUS and MCU in the same setting between August 2016 and May 2017. All ceVUS were performed with Philips Affiniti 70 ultrasound system. SonoVue was used as the contrast agent for ceVUS. All the patients then received MCU under fluoroscopic screening using iodinated contrast. Follow-up phone interviews were done up to 5 days after the examination. Results: In total, 22 patients, including 18 male and four female patients (age range, 19 days to 24 months) were included, giving a total of 44 pelvi-ureteric units (PUUs) examined. VUR was detected in four out of the 44 PUUs. Except for one PUU which showed grade 2 VUR on ceVUS but grade 1 VUR on MCU, all other PUUs showed concordant findings on both examinations. Regarding detection of VUR irrespective of its severity, ceVUS showed sensitivity of 100% and specificity of 100% in our cohort. Other findings included: hydronephrosis (n=10), ureterocoele (n=1), multicystic dysplastic kidney (n=1), renal cysts (n=3), and urethral diverticulum (n=1). All the patients tolerated the procedures well with no significant complications from the procedures. Conclusion: ceVUS is accurate, safe, and allows one-stop anatomical and functional assessment. Our unique case of urethral diverticulum detected on ceVUS also expanded our understanding in the utility of ceVUS for urethral pathology.