Predictive value of ultrasound findings for high-grade vesicoureteral reflux in children: a retrospective cross-sectional study in Saudi Arabia.

BACKGROUND: Voiding cystourethrography (VCUG) remains the gold standard for diagnosing vesicoureteral reflux (VUR) but is invasive, involves ionizing radiation, and may cause considerable discomfort in children. Ultrasound offers a non-invasive alternative, although its ability to predict severe reflux remains uncertain. This study evaluated the predictive value of ultrasound findings for the detection of high-grade VUR and identified sonographic predictors associated with severe reflux in children. METHODS: A retrospective cross-sectional study was conducted involving pediatric patients aged 0-14 years who underwent both renal and bladder ultrasound and VCUG between January 2018 and December 2024 in tertiary and secondary healthcare facilities in the Central Region of Saudi Arabia. Ultrasound variables including hydronephrosis severity, ureteral dilatation, cortical thinning, renal scarring, and bladder abnormalities were compared with VCUG findings. Chi-square analysis, multivariate logistic regression, receiver operating characteristic (ROC) analysis, and diagnostic performance measures were performed. RESULTS: A total of 406 children were included, with high-grade VUR identified in 50 patients (12.3%) on VCUG. Severe right and left hydronephrosis, ureteral dilatation, right cortical thinning, right renal scarring, and bladder distention were significantly associated with high-grade VUR (p < 0.05). Multivariate analysis identified left hydronephrosis (OR = 4.54), right hydronephrosis (OR = 4.18), bladder distention (OR = 4.18), and right renal scarring (OR = 3.76) as independent predictors. The combined ultrasound model demonstrated good discriminative ability (AUC = 0.824), sensitivity of 78.0%, specificity of 76.4%, positive predictive value of 31.7%, negative predictive value of 96.1%, and overall accuracy of 76.6%. CONCLUSION: Multiparametric ultrasound is an effective screening tool for excluding high-grade VUR and may reduce unnecessary VCUG examinations but should not be seen as a replacement for VCUG.