Predictability of Vesicoureteral Reflux Using Interlobar Renal Arterial Resistive Indices in Sonographically Normal Pediatric Kidneys-Preliminary Results

Objective: To prospectively evaluate the diagnostic utility of interlobar renal arterial resistive index values, in predicting the presence of vesicoureteral reflux in children with sonographically normal appearing kidneys. Methods: We investigated 35 children with a history of urinary tract infection with grayscale and color Doppler ultrasound (US) followed by a standard voiding cystouretherogram to assess the presence of vesicoureteral reflux. All renal units (individual kidneys) were morphologically normal without evidence of hydronephrosis. Resistive index (RI) was measured at the level of the interlobar arteries. Results: Of a total of 67 kidney units, 3 kidney units yielded no diagnostic results due to technical factors (crying, agitation). 46 kidney units (69%) were not associated with any degree of reflux. 17 kidney units (25%) were associated with low-mid grade reflux (grades I III). 4 kidney units (6%) were associated with high grade reflux (grades IV V). No statistically significant correlation was found between the interlobar resistive indices of sonographically normal appearing kidneys and the presence, absence, or degree of vesicoureteral reflux. Conclusions: The results of this study suggest that resistive index measurements taken in the interlobar arteries of sonographically normal appearing kidneys cannot be used to predict the presence or absence of vesicoureteral reflux.