Carotid Ultrasound & Doppler Testing (IMT)

A carotid ultrasound specifically examines the carotid arteries, which carry blood from the heart to the brain and are located on either side of the neck. Plaque buildup in these arteries can make them narrower, reducing blood flow to the brain. If either of the carotid arteries becomes blocked, you may experience a stroke.

A carotid ultrasound is painless and typically takes about 30 minutes. The technician uses an external probe called a transducer to bounce high-frequency sound waves off your red blood cells (a technology known as Doppler testing), generating images of your arteries in action. The resulting images, which appear on a monitor, are much more detailed than those from a traditional ultrasound.

Narrowed blood vessels can be extremely dangerous and can lead to a variety of medical emergencies, so if you’re at risk for cardiovascular disease, it’s important to have a carotid ultrasound. This procedure can also be used to locate blood clots, detect artery abnormalities, and evaluate the success of certain surgeries.

In some cases, the ultrasound technician may also perform a carotid intima-media thickness (IMT) measurement, which assesses the thickness of the carotid arteries’ inner layers. A carotid IMT test can help your cardiologist estimate your risk of a future cardiovascular event, such as a heart attack or stroke, and develop a treatment plan to avoid one.