The Carotid Doppler exam uses sound frequency, in a range that is higher
than human beings are able to hear, to produce images of the carotid arteries
in the neck on a viewing screen. Carotid Doppler studies are used to identify
blocked or reduced blood flow in the arteries of the neck that could cause
stroke. This test is also used to evaluate symptoms of dizziness, vision
changes and loss of balance that may be caused by impeded or restricted
blood flow through these vessels.