Acute Tc 99m DMSA scintigraphy in children with a first pyelonephritis

The aim of this study was to evaluate the results of Tc 99m dimercaptosuccinic acid scintigraphy (DMSA) in children with a first episode of acute pyelo-nephritis (APN) and the correlation with the laboratory parameters and ultrasound. Method: The study included 143 children hospitalized with the clinical diagnosis of APN, first episode, and a DMSA scan performed while infected (7 days). 66% females with a median age 14 months, range 8 days - 12 years old. DMSA was considered the gold standard for the detection of cortical lesions, and we did the correlation with C-reactive protein (CRP), erythrocyte sedimentation rate (VHS), white blood count (WBC) and ultrasound. The results were expressed as mean plus or minus 1 standard deviation (SD). The comparison among different groups was performed by a Mann Whitney test. Results: 79% of the population had a positive DMSA scan. There were not differences between the parameters of laboratory in the children with a positive DMSA scan and a normal DMSA scan , except in CRP ( p<0.0001). The sensitivity, specificity, positive prediction value (PPV), negative prediction value (NPV) of the different parameters are presented. Conclusions: 1. The abnormality of the DMSA was 79%, however there is a relatively high fraction with a normal DMSA. 2. The conventional laboratory tests have a moderate to high PPV, but a low NPV to detect cortical renal lesions. The CRP has the better parameters