DETECTION OF PERMANENT DAMAGE IN KIDNEYS WITH VESICOURETERAL REFLUX BY QUANTITATIVE SINGLE-PHOTON EMISSION COMPUTERIZED-TOMOGRAPHY (SPECT) UPTAKE OF (99M)TECHNETIUM LABELED DIMERCAPTOSUCCINIC ACID

Purpose: We determined the level of functional damage to the kidney wh ich inhibits further growth. Materials and Methods: Renal functional v olume and percent uptake of 34 kidneys with reflux were studied by per forming sequential quantitative single photon emission computerized to mography 2 times at a mean interval of 3.2 years. Results: Change in v olume between the initial and repeat studies was 27.2 +/- 28.4% in all 34 kidneys. Change in volume was less than 7% in 8 kidneys and greate r than 14% in 26. Receiver operating characteristic curve analysis ind icated that 15.6% kidney uptake was associated with 75% sensitivity, 1 00% specificity and 94% accuracy in distinguishing kidneys with more t han 7% from those with less than 7% change in volume. The value of kid ney uptake of less than 15.6% was 100% in predicting less than 7% chan ge in volume (positive predictive value) and the value of kidney uptak e greater than 15.6% was 93% in predicting more than 7% change in volu me (negative predictive value). Conclusions: Kidney uptake of less tha n 15.6% represents irreversible impairment of renal growth and indicat es permanent damage in kidneys with vesicoureteral reflux.