Atherosclerosis in neck blood vessels. 3D computed tomography (CT) scan and angiogram of the neck arteries (orange) and veins (red) in an 80-year-old man with atherosclerosis. The scan shows the carotid blood vessels in left anterior oblique view. At centre is the carotid bulb (where the internal and external carotid arteries branch off the common carotid artery). The irregular appearance of the arterial and venous walls indicate the presence of atheromatous plaques, deposits of cholesterol and fats on the blood vessel walls. This narrowing (stenosis) is a risk factor for strokes.