Contrast-Enhanced Voiding Urosonography and Radionuclide Cystography for Diagnosing Vesicoureteral Reflux Using VCUG as the Reference Standard: Systematic Review and Meta-Analysis

BACKGROUND. Fluoroscopic voiding cystourethrography (VCUG) is the most commonly used imaging test for the detection of vesicoureteral reflux (VUR) in children, although contrast-enhanced voiding urosonography (ceVUS) and radionuclide cystography (RNC) are also used for this purpose. OBJECTIVE. The purpose of this study was to perform a systematic review and meta-analysis to determine the sensitivity and specificity of ceVUS and RNC for the detection of pediatric VUR using VCUG as the reference standard. EVIDENCE ACQUISITION. The Embase, MEDLINE, BIOSIS, Scopus, Cochrane, and Web of Science databases were searched from their date of inception through June 9, 2024, for studies performed in children that reported the sensitivity and specificity of ceVUS or RNC for the detection of VUR using VCUG as the reference standard. Studies' risk of bias was assessed using the QUADAS-2 tool. Diagnostic performance data were extracted from each study on a kidney-ureter level if available and on a patient level otherwise. Pooled sensitivity and specificity were estimated using bivariate random-effects models. Metaregression analysis was performed. EVIDENCE SYNTHESIS. Of 2757 unique studies screened, 42 studies with 3124 total children were included in the final analysis. Twenty-six and 16 studies were at overall high and low risk of bias, respectively. Using VCUG as the reference standard, ceVUS (37 studies) had pooled sensitivity of 86% (95% CI: 82-90%) and pooled specificity of 92% (95% CI: 90-94%). Using VCUG as the reference standard, RNC (five studies) had pooled sensitivity of 81% (95% CI: 62-92%) and pooled specificity of 89% (95% CI: 75-95%). In metaregression analysis, publication year, sample size, patient age, and overall risk of bias had no significant association with sensitivity or specificity for either ceVUS or RNC (all p > .05). CONCLUSION. Pooled diagnostic performance estimates were derived for the available imaging tests for detecting VUR. However, most studies had an overall high risk of bias, highlighting a need for higher quality comparative studies. CLINICAL IMPACT. The results may help shape evolving guidelines and inform selection among the available imaging tests in clinical practice.