With a wider vessel, the Doppler shift is broadened since there will now be {HEAD ~ blood cells} travelling at different velocities across {TAIL ~ the diameter} of the vessel 
travelling across
With a wider vessel , the Doppler shift is broadened since there will now be { HEAD ~ blood cells } travelling at different velocities across { TAIL ~ the diameter } of the vessel
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH