Hepatocellular carcinoma: evaluation with color Doppler US and MR imaging

Fifteen patients with hepatocellular carcinoma underwent examination with color Doppler ultrasound (US), magnetic resonance (MR) imaging, dynamic computed tomography (CT), and angiography. Doppler signals ranging from 0.22 to 3.48 kHz could be obtained from within the tumor in 14 of 15 patients. The resistive index was 0.38-0.77. Color Doppler signals were visualized in nine of 15 lesions with a Doppler shift greater than 0.7 kHz. The Doppler signals and the resistive index of the tumor vessels became lower as the vessels progressed into the center of the lesion. The appearance of tumor vessels recognized on MR images obtained with gradient-recalled acquisition in the steady state (GRASS) in 11 of 15 lesions was compared with that on CT scans and angiograms. Tumors that were hyperintense on GRASS images obtained with a flip angle of 15 degrees transmitted Doppler signals of considerably higher amplitude compared with the isointense lesions. Both color Doppler US and MR imaging provided useful information for characterizing intratumoral blood flow.