Resistive indices in the evaluation of infants with obstructive and nonobstructive pyelocaliectasis

Diagnosing obstructive uropathy by renal resistive indices calculated from duplex Doppler sonographic waveforms has been supported as well as challeng ed in the radiology literature relating to adults. Despite reports of norma lly higher resistive indices in children as compared to adults, two studies have documented high sensitivity and specificity of renal Doppler sonograp hy in the diagnosis of obstructive uropathy in children, using the same dis criminatory criterion of a resistive index of 0.7 or greater as used in adu lts. We evaluated 43 infants with significant or bilateral pyelocaliectasis secondary to both obstructive and unobstructive uropathy and found no sign ificant difference in the mean resistive indices or the mean difference in resistive indices of two kidneys in one patient. We conclude that Doppler s onography in infants has no value in differentiating obstructive from nonob structive pyelocaliectasis.