Comparing the Accuracy of Doppler Resistance Index of the Renal Artery with DSMA Scintigraphy in children with Febrile UTI and Prediction of VUR and acute Pyelonephritis

Background and UTI is one of the most common bactctrial infections in pediatrics. Febrile urinary tract infection can produce severe renal complications when unrecognized or untreated. Acute pyelonephritis (APN) and reflux are two synergistic factors in the destruction of kidneys of children. There are no certain specific diagnostic laboratory tests and clinical symptoms for diagnosis of UTI. There are several diagnostic methods for APN and reflex in pediatrics, including ultrasonography. IVP, VCUG, CT, Doppler and DMSA scintigraphy. Most of these methods are associated with the danger of exposure to radiation. In this study, we assessed and compared the accuracy of renal artery resistive index (RI) in doppler ultrosonography with DMSA scan and vcug to the diagnosis of APN and reflux in pediatrics patients. In this diagnostic study, we assessed 72 kidneys from 36 children (28 girls and 8 boys, age 19 days to 27/19 months) with febrile UTI admitted in Booalisina Hospital of Sari in 2005 to 2006. All patients underwent cysto-renal ultrasonography and Doppler ultrasonography. They Also underwent VCUG and DMSA scan to rule out vesicoureteral reflux and APN respectively. The data recorded in separate questionnaires and were analyzed using spss- statistical software. The results concluded that DMSA was positive in 34.7% of children with febrile and confirmed clinical impression, while Doppler sonography was positive in 33.3% of cases. The specificity and sensitivity of Doppler sonography were 64% and 83%, while the positive predictive value and negative predictive value were 66.7% and 81.3% respectively. According to the results of this study, Doppler RI>0.7 in pediatrics with febrile UTI and clinically suspected APN are in need of careful antibiothic therapy and must be controlled by DMSA scan. DMSA is not necessary in children with Doppler RI <0.7 and they must be treated for possible cystourethral infection. Thus, there is a significant relationship between increased RI and the severity of renal involvement. Considering, that 83% sensitivity and 81.3% predictive value of Doppler RI measurement to diagnosis of APN and scaring, it is concluded that Doppler index (RI) measurement to rule out of APN is valuable.