Ultrasound has a good access to the extracranial portion of these vessels.
Atherosclerosis usually involves the proximal ICA and carotid bulb.
The left CCA originates from the arch of aorta. Right CCA originates from the brachiocephalic artery. The ECA is antero-medial, and has multiple branches. This pattern indicates that most of the blood cells are moving at similar velocities. The window pattern seen in the Doppler spectrum of a normal carotid artery is due to laminar flow.