Keywords : aliasing, angle, boundary layer, center stream sampling, color Doppler, color gain, color, Doppler equation, Doppler gate, Doppler shift, Doppler, eddy currents, flow reversal, helical flow, laminar flow, non-laminar flow, Nyquist limit, power Doppler, PRF, pulse repetition frequency, sample volume gate, Scale, separation, spectral broadening, spectral Doppler gain, spectral Doppler, velocity scale, vessel wall discrimination, wall filter, wall motion