Diagnostic modalities of childhood urinary tract infection: clinical versus imaging

ABSTRACT

Seventy six infants and children with febrile urinary tract infection [UTI] were studied aiming at investigating the most reliable imaging approach for febrile UTI and to evaluate the reliability of clinical and laboratory diagnosis of acute pyelonephritis [APN] versus imaging diagnosis using renal scan with dimercaptosuccinic acid labeled with technetium 99m [99mTc-DMSA] as standard reference. Positive radiological findings were documented in 36 out of the 76 studied patients [47.37%]. Out of the 76 studied patients APN was confirmed in 28 patients [36.84%] by 99mTc-DMSA scanning. Renal ulrasonography [US] detected upper urinary tract abnormalities in 19.74% [15/76] of patients, all of them had DMSA positive scan for APN. Micturating cystourethrography [MCUG] demonstrated vesicoureteral reflux [VUR] in 23.68% [18/76] patients. Positive DMSA scan for APN was documented in 61.11% [11/18] of patients with VUR. The sensitivity of US compared to 99mTc-DMSA scan for detection of acute renal pa-renchymal changes was 53.57%, the specificity was 100% and the accuracy was 76.79%. Compared to 99mTc-DMSA scan, clinical and laboratory diagnosis of APN had a sensitivity of 67.85%, specificity of 72.92% and accuracy of 70.39%. In conclusion: the diagnosis of APN among infants and children with febrile UTI based on clinical and laboratory observations is insufficient and requires imaging studies. The three imaging modalities chosen are complementary and are needed for establishing a diagnostic approach for childhood UTI. The results of this study also emphasize the value of 99mTc-DMSA scintigraphy in the initial evaluation of febrile UTI