A case of Caroli's disease: usefulness of color Doppler sonography for evaluating the malformation of the intrahepatic bile ducts.

Caroli's disease is a rare congenital disorder with multiple cystic dilatations of the intrahepatic bile ducts. In addition to the nonobstructive localized dilatation of the bile ducts, intraluminar bulbar protrusions of the wall and bridge formation across dilated lumina have been demonstrated on sonography and computed tomography. We present a case in which color Doppler sonography clearly showed a blood flow signal toward the periphery of the liver in the protrusion of the dilated intrahepatic bile ducts. Color Doppler sonography is a useful noninvasive method for evaluating the malformation of Caroli's disease.