RESUMO
OBJECTIVE: The objective of this study was to compare the findings of renal ultrasonography and 99mTc-DMSA renal scintigraphy in children with their first acute febrile urinary tract infection to determine which method is better in detecting patients at risk of renal injury or reflux. PATIENTS AND METHODS: Thirty-three children between 0.2 and 12.3 years of age with their first acute febrile urinary tract infection were studied by means of clinical and laboratory assessment, renal ultrasonography and 99mTc-DMSA renal scintigraphy. In 24 patients (72.7%) a voiding cystourethrography was made. The patients were divided into two groups, those under 2 years of age (n = 14) and those over 2 years old (n = 19). RESULTS: Cortical scintigraphy showed renal changes in 23 patients (69.7%) and ultrasonography showed renal changes in 2 (6.1%; p < 0.05). Children over 2 years of age had a higher incidence of renal lesions than did younger children (84.2% vs 50%; p < 0.05). There were no differences between girls and boys. Reflux was demonstrated in 13 patients (54.2%). Among those kidneys which presented abnormal cortical scintigraphy, vesicoureteral reflux was present in 76.5% of the studies. Furthermore, of those with abnormal ultrasonography vesicoureteral reflux was present in 17.6%. CONCLUSIONS: We found a high incidence of renal involvement in children with their first acute febrile urinary tract infection. The cortical scintigraphy is more sensitive than ultrasonography in detecting renal changes. The incidence of vesicoureteral reflux in febrile urinary tract infection is high. When there is a renal cortical defect the risk of reflux is higher. This suggests that cortical scintigraphy should be added to the initial examination of children with their first acute febrile urinary tract infection and this could be supplemented by voiding cystourethrography alone, with ultrasonography having a secondary role.
