Renal scintigraphy with DMSA 99 mTc and the direct radionuclide cystogram in children with recurrent urinary tract infections

The aim of this study was to correlate the results of Renal Scintigraphy (RS) and the Direct Radionuclide Cystogram (DRC) in children with recurrent urinary tract infections. Method: we analyse 92 children, 82 % females , with ages ranging from 1 month- 12 years old (mean:4,3 years old). Both techniques were performed conventionally with a gammacamera/ computer system. We determined the concordance or discordance between them, and the positive and negative predictive value (PPV, NPV ) of one method with respect the other. For statistical analysis we use Chi square and MacNemar test. Results: 45 % of the RS were abnormal, and the 27 % of DRC was positive. We found a concordance of the results in both techniques in 70 % (p< 0.001) .For the RS vs DRC the PPV was 46% and the NPV was 88%. For the DRC vs RS the PPV was the 76 % and the NPV was 67%. Conclusions. 1.- : 1.- the normality of RS is a better predictor of normality than DRC. 2.-The abnormality of DRC predicts better the abnormality of RS than the inverse. 3.- The results of both techniques show a significant concordance (author)