Fig. 4
As Doppler beam-flow angles decreased, decreases in spectral broadening were seen. a Image of Doppler velocity measurement taken at a 64° beam-flow angle without the use of slanted gel pads shows spectral broadening throughout nearly the whole velocity range (arrow). b Image of Doppler velocity measurement taken at a 44° beam-flow angle with the use of a slanted gel pad (star) shows much decreased spectral broadening seen mostly throughout only the upper velocity range (arrow)