Hemodynamic imaging with pulsatility-index and resistive-index color Doppler US.

Pulsatility index and resistive index were mapped with color Doppler ultrasound (US) and compared with spectral Doppler US findings. In the carotid arteries and/or kidneys in 12 healthy subjects, the pulsatility index and resistive index were estimated from mean frequency shifts and mapped into "cool-warm" or "rainbow" color scales. Surveys that depicted intervessel variations in a complex vascular field were useful in deciding where to perform spectral Doppler US. Intravessel variations were consistent with fluid dynamic theory.