Figure 4a. Hepatic artery stenosis. (a) Color and spectral Doppler image of the main hepatic artery obtained at the anastomosis shows a focal stricture with aliasing in the middle portion of the main hepatic artery (arrow). The Doppler spectrum shows an elevated peak velocity (220 cm/sec) and spectral broadening, findings consistent with turbulence. (b) Superselective digital subtraction angiogram of the main hepatic artery shows the stenosis (arrow). (c) Color and spectral Doppler image of the left intrahepatic artery shows a tardus-parvus waveform with a prolonged acceleration time and decreased resistive index.