The Role of Ultrasonography in Predicting Vesicoureteral Reflux

OBJECTIVE To evaluate the accuracy of renal and bladder ultrasonography (RBU) in predicting vesicoureteral reflux (VUR) in infants and children. MATERIALS AND METHODS A total of 134 children who had VUR demonstrated on voiding cystourethrography (VCU) and also had RBU within 1 month of the VCU were included in the study, which took place between January 2005 and December 2012. VUR and hydronephrosis were graded with standard methods on VCU and RBU, respectively. Using VCU findings of reflux as the gold standard, diagnostic accuracy measures were performed for hydronephrosis and ureteral visualization on RBU, including sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. RESULTS Reflux grade was significantly associated with the degree of hydronephrosis (P = .0032). The sensitivity, negative predictive value, and accuracy of ultrasonography in predicting reflux was significantly higher for grade IV+ or grade V reflux compared with lower reflux grades. Also, the specificity of ultrasonography in predicting reflux was constant and at high level across all reflux grades, suggesting that ultrasonography is a good diagnostic screening tool. CONCLUSION Normal RBU is rare with grade IV-V reflux, and moderate to severe hydronephrosis is rare with reflux grades <IV. RBU is a valid screening test for the selection of patients with a first urinary tract infection who should undergo VCU. Diagnosis of grade IV and V reflux will be delayed in very few cases, using a definition of abnormal RBU to include all degrees of hydronephrosis (Society for Fetal Urology classification). (C) 2014 Elsevier Inc.