The improved depiction of renal parenchymal vascularity with power Doppler imaging facilitates the sonographic detection of hypovascular lesions such as pyelonephritis, renal abscesses, and infarction. However, the finding of diminished or absent lobar perfusion may be present in all of these entities; thus, the abnormalities shown on power Doppler imaging are often nonspecific. Clinical and laboratory data are often essential to establish the correct diagnoses. Contrast-enhanced CT remains useful for distinguishing these various disorders.