We retrospectively reviewed 32 cases with appearance of focally increased color Doppler signal on intrarenal CDUS from May 1, 2007, to February 28, 2009. Indications for intrarenal CDUS in 32 cases were suspicion of renovascular hypertension, investigation of complications related to renal biopsy, or hematuria. Characteristics of the color Doppler signal, relationship between color Doppler signal and renal vessels, and the spectral Doppler sampled at the anatomic site of the focal color signal were analyzed