Assessment of renal resistive-index in children with vesicoureteral reflux.

Aim: To assess the value of the renal resistive index (RI) in evaluating renal perfusion in children with vesicoureteral reflux (VUR). Method: We investigated 92 kidneys in 46 children with VUR with a mean age of 6 +/- 4 years. The RI was measured at the level of the interlobar-/arcuate-arteries using a color Doppler unit Acuson 128 XP/10 (Mountain View, Gal.). The results of the RI-measurement were correlated to the findings in renal scintigraphy. Results: Children with VUR grade I-III showed RI-values less than the normal physiological upper limit of 0.7. Patients with VUR grade IV-V demonstrated a significant increased RI-value of 0.77 +/- 0.07 (p < 0.0001). The correlation of the RI-measurements with the scintigraphic findings revealed a correlation-coefficient of r(2) = 0.61. Conclusion: Changes of renal perfusion were only found in high-grade VUR, demonstrating a good correlation with the scintigraphic findings. Therefore color Doppler ultrasound seems to be helpful in the follow-up of patients with high-grade reflux.