Renal Doppler ultrasonography in infants with hydronephrosis

The objective was to evaluate the importance of obstruction in unilateral hydronephrosis by using renal Doppler ultrasonography. A total of 19 infants were examined. It was revealed that patients of group with obstruction have in the affected kidney a higher mean resistive index [RI = 0.77 +/- 0.04] than in the healthy kidney [RI = 0.69 +/- 0.02] [p < 0.001]. In patients of group with nonobstructive dilatation this difference was not observed. In infants it is not possible to evaluate only absolute changes of the resistive index. It is much more useful to compare values of RI of both kidneys using the above indices. The determination of RI, RIR and delta RI can be helpful in distinguishing obstructed from non-obstructed hydronephrosis.