Evaluation of Renal Resistivity Index Before and After Voiding Cystoureterography Examination in Patients With Vesicoureteral Reflux

Vesicoureteral reflux (VUR) occurs commonly in children and can cause significant renal damage. The purpose of this study is to assess the changes in renal vasculature with spectral Doppler sonography in patients with VUR. In addition, the possible effects of voiding cystoureterography (VCU) on the kidneys in patients with VUR are investigated by calculating renal resistivity index (RI) values before and after VCU using spectral Doppler sonography. In this prospective study, 114 kidneys of 58 children ages 0 to 16 years were included. The RI values that were calculated before and after VCU and RI values in different grades of VUR were compared statistically. In patients with VUR, the renal parenchymal RI values before and after VCU were significantly higher than those in patients without VUR ( P < .05). The mean pre-VCU RI values were 0.68 ± 0.03 and 0.65 ± 0.05 in patients with VUR and in the control group, respectively, and the mean post-VCU RI values were 0.68 ± 0.03 and 0.65 ± 0.04 in patients with VUR and in the control group, respectively. Calculating renal RI values from arcuate or interlobar renal arteries with spectral Doppler sonography while the patients are in a supine or lateral decubitus position is a useful technique in patients with VUR, being significantly higher in high-grade VUR patients than in low-grade VUR patients. There is no significant effect of the contrast agent reaching the renal calycial system during VCU examination on renal RI values.