Doppler waveform of normal ECA (External carotid artery):

The ECA (right ECA here) shows very high (compared to ICA) PSV values and hence a sharp systolic peak and rather poor flow during diastole (seen as low EDV or end diastolic velocity). The PSV (Vmax) in this case is = 105/cms./sec. The normal range of PSV (peak systolic velocity) for the ECA is from 77 cms./sec. to 115 cms./sec.

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