The potential harm of using US as the only imaging for UTI is the poor sensitivity for VUR and pyelonephritis/scarring [25-30,64]. There are limited data showing inconsistent results on the sensitivity of US in the detection of dilated VUR [65,66]. Grayscale US identifies approximately 25% of the patients with acute pyelonephritis and approximately 40% of the patients with chronic parenchymal scarring [29,31,67-72]. Urinary Tract Infection-Child In a retrospective study of 2,259 children <5 years of age, sensitivity of US was related to criteria for the definition of a normal study. With the use of the most relaxed criteria (25% abnormal), US had a sensitivity of 28% (specificity of 77%), and with the most stringent criteria (4% abnormal), US had a sensitivity of 5% (specificity of 97%) [31]. Assuming a 40% prevalence of VUR and a 20% recurrent rate of UTIs in 100 children who have US, up to 11 children will have positive US studies that will be followed by a VCUG study, of which 8 will be positive for VUR. Two years of a prophylactic antibiotic will decrease recurrent UTIs from up to 2 children to 1 child. This means that 1 child will benefit from US and an additional 3 children that may benefit from prophylactic antibiotic will not be treated. In addition, with the increased use of prenatal US screening, the yield of detection of unknown renal abnormalities in children with UTIs has decreased [73]. A few studies with small series of children suggest good correlation between power Doppler and Tc-99m DMSA for pyelonephritis [74,75]. Other studies, however, demonstrated low sensitivity for pyelonephritis and low prediction for development of renal scarring [49,76,77]. Therefore, the use of power Doppler as a replacement for DMSA is not useful [26,49,76]. The NICE guidelines for UTI do not recommend US in evaluation of UTI in children >6 months of age if typical infection [16]. The AAP guidelines recommend US for children with a febrile UTI from ages 2 to 24 months [41].
Urinary Tract Infection Child. The potential harm of using US as the only imaging for UTI is the poor sensitivity for VUR and pyelonephritis/scarring [25-30,64]. There are limited data showing inconsistent results on the sensitivity of US in the detection of dilated VUR [65,66]. Grayscale US identifies approximately 25% of the patients with acute pyelonephritis and approximately 40% of the patients with chronic parenchymal scarring [29,31,67-72]. Urinary Tract Infection-Child In a retrospective study of 2,259 children <5 years of age, sensitivity of US was related to criteria for the definition of a normal study. With the use of the most relaxed criteria (25% abnormal), US had a sensitivity of 28% (specificity of 77%), and with the most stringent criteria (4% abnormal), US had a sensitivity of 5% (specificity of 97%) [31]. Assuming a 40% prevalence of VUR and a 20% recurrent rate of UTIs in 100 children who have US, up to 11 children will have positive US studies that will be followed by a VCUG study, of which 8 will be positive for VUR. Two years of a prophylactic antibiotic will decrease recurrent UTIs from up to 2 children to 1 child. This means that 1 child will benefit from US and an additional 3 children that may benefit from prophylactic antibiotic will not be treated. In addition, with the increased use of prenatal US screening, the yield of detection of unknown renal abnormalities in children with UTIs has decreased [73]. A few studies with small series of children suggest good correlation between power Doppler and Tc-99m DMSA for pyelonephritis [74,75]. Other studies, however, demonstrated low sensitivity for pyelonephritis and low prediction for development of renal scarring [49,76,77]. Therefore, the use of power Doppler as a replacement for DMSA is not useful [26,49,76]. The NICE guidelines for UTI do not recommend US in evaluation of UTI in children >6 months of age if typical infection [16]. The AAP guidelines recommend US for children with a febrile UTI from ages 2 to 24 months [41].