Color Doppler Ultrasound Evaluation of Ureteral Jet Angle to Detect Vesicoureteral Reflux in Children

Purpose: Vesicoureteral reflux is the most common urinary tract abnormality in children. Although voiding cystourethrography is the gold standard for diagnosing reflux, this approach is invasive. We evaluated color Doppler ultrasound measurement of ureteral jet angle as a noninvasive screening tool for detecting reflux. Materials and Methods: We retrospectively evaluated 125 children (250 renal units) who presented with urinary tract infections or hydronephrosis. All patients underwent color Doppler ultrasonography and voiding cystourethrography. Ureteral jet angle was measured as angle between the direction of the ureteral jet and interureteral ridge. Results: Reflux was diagnosed in 80 patients (117 renal units). Mean +/- SD ureteral jet angle was significantly greater in refluxing units (67.9 +/- 18.7 degrees) than in nonrefluxing units (47.8 +/- 17.3 degrees, p < 0.0001). Angle value in each reflux grade became significantly greater according to grade (p < 0.0001). Overall ability of ureteral jet angle to detect grade III to V and grade IV/V reflux, as given by the area under the receiver operating characteristic curve, was 0.81 and 0.88, respectively. A cutoff angle of 55 degrees or greater detected grade III to V and grade IV/V reflux with a sensitivity of 85.5% and 94.7%, respectively. A cutoff angle of 70 degrees or greater diagnosed grade IV/V reflux with a sensitivity of 81.6% and a specificity of 82.7%. Conclusions: Color Doppler ultrasound measurement of ureteral jet angle represents a simple and noninvasive method that is applicable as a screening tool to detect high grade vesicoureteral reflux in children.