Power Doppler sonographic evaluation of acute pyelonephritis in children.

Twelve children admitted to the hospital with a clinical diagnosis of acute pyelonephritis were studied with power Doppler sonography and either renal cortical scintigraphy or contrast-enhanced CT. Imaging studies were normal in four patients. A single focus of pyelonephritis was seen by cortical scintigraphy in five children, with a matching defect observed on power Doppler sonography in four patients and a small focus of infection not detected on power Doppler sonography in one child. Multifocal pyelonephritis was identified correctly by power Doppler sonography in two children, although this imaging modality underestimated the extent of involvement in one of the children. One child with diffuse pyelonephritis had a normal power Doppler sonogram. In this study, power Doppler sonography had an overall sensitivity of 75% and specificity of 100% in the evaluation of children with acute pyelonephritis.