Carotid ultrasound is a painless test that uses high-frequency sound waves to create pictures of the insides of the two large arteries in your neck. These arteries, called carotid arteries, supply your brain with oxygen-rich blood.
Carotid ultrasound shows whether a substance called plaque has narrowed your carotid arteries. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. Plaque builds up on the insides of your arteries as you age. This condition is called carotid artery disease.
A carotid ultrasound can show whether plaque buildup has narrowed one or both of your carotid arteries and reduced blood flow to your brain. If plaque has narrowed your carotid arteries, you may be at risk of having a stroke. That risk depends on how much of your artery is blocked and how much blood flow is restricted.