RENAL DOPPLER ULTRASOUND IN CHILDREN WITH OBSTRUCTIVE UROPATHY - EFFECT OF INTRAVENOUS NORMAL SALINE FLUID LOAD AND FUROSEMIDE

Purpose: We studied the effect of hyperhydration with normal saline an d furosemide on renal resistive index in children with obstructive uro pathy. Materials and Methods: (99m)Technetium-mercaptoacetyltriglycine diuretic renography and Doppler ultrasound were done in 27 children ( 54 renal units) with unilateral or bilateral hydronephrosis. Doppler s tudies were performed at baseline, and after infusion of normal saline and administration of furosemide. Half-time drainage, considered the gold standard for the diagnosis of renal obstruction, was compared to resistive index. Results: There was a positive correlation between hal f-time and resistive index on both Doppler studies. With a resistive i ndex of 0.70 as the critical value for predicting renal obstruction 82 versus 100% sensitivity (p < 0.006), 63 versus 94% specificity (p < 0 .04) and 76 versus 98% overall accuracy (p < 0.0005) were obtained for Doppler studies at baseline and after induced diuresis, respectively. All children with false-positive results were younger than age 4 year s. Conclusions: Doppler ultrasonography after hyperhydration with norm al saline and furosemide is an accurate method for diagnosing renal ob struction in children. It is more sensitive, specific and accurate tha n baseline Doppler studies.