Carotid Ultrasound (aka Carotid Intimal Media Thickness or CIMT) is a simple, safe and painless non-invasive test that utilizes ultrasound waves to detect the presence and extent of atherosclerosis (plaque build-up) in your carotid (neck) arteries.
You have 2 carotid arteries which are located one on each side of your neck. Their role is to deliver blood from your heart to your brain.
Cross-sectional illustration of the Carotid arteries supplying oxygenated blood to the brain.
Atherosclerosis is the major underlying cause of heart attacks and strokes, and it is characterized by the accumulation of cholesterol, white blood cells and cell debris in the inner lining of the arterial wall. This leads to cholesterol plaque formation which causes blockages in the arteries supplying blood to vital organs such as the heart, brain and kidneys. Plaque ruptures may cause blood clotting (thrombosis) resulting in complete cessation of blood flow. This can lead to a heart attack (acute myocardial infarction) if it occurs in the heart arteries or a stroke if it occurs in the arteries supplying the brain.
Using B-mode two-dimensional ultrasound with frequencies ranging between 5 to 15MHz, the intima and media linings of the carotid arteries are measured. This provides valuable information about the amount of atherosclerosis present in the arterial wall. This will help our doctor determine a treatment to lower your stroke and heart attack risk.
Example of a Normal Carotid Intimal Media Thickness
Example of an Abnormal Carotid Intimal Media thickness with Cholesterol plaque causing narrowing of the vessel lumen and blood flow.
What are the benefits of a Carotid Ultrasound?
Atherosclerosis in the Carotid arteries leading to clot formation (thrombosis) and stroke.
Risk stratification for stroke and heart attack
Atherosclerosis often starts at a young age, many years before clinical symptoms of cardiovascular disease becomes manifest. Detecting and measuring atherosclerosis in asymptomatic individuals may be helpful to assess the risk of future cardiovascular events and to guide preventive measures.
As atherosclerosis is very often widespread, the carotid arteries are useful surrogate markers for the atherosclerotic burden in the other arteries.
Guide treatment of hyperlipidemia (high cholesterol)
Many patients often struggle with the decision of whether to start cholesterol-lowering drugs when they have hyperlipidemia. The presence of atherosclerotic plaques in the carotid arteries portends a higher risk of developing complications such as a heart attack or stroke.
Lipid-lowering drugs such as statins have been shown to significantly reduce the progression of atherosclerosis and should be started in the absence of any clinical contraindications.
Who will benefit from this test?
- Patients with symptoms suggestive of stroke (eg weakness, numbness, difficulty walking or speaking)
- Patients at risk of stroke and heart disease
- Diabetes mellitus
- High blood pressure
- High cholesterol
- Chronic smoking
- Positive family history of premature heart disease or stroke
- Abnormal sounds in your carotid arteries (bruit)
- Routine health screening to assess the risk of stroke or cardiovascular events such as heart attack.
How to prepare for the test
- Apart from coming for the test in comfortable collarless T-shirt, no other preparation is required.
- Avoid wearing a necklace or dangling earrings.
How is the test performed?
- Carotid Ultrasound is relatively straightforward, safe and inexpensive. No radiation is involved, and no contrast is needed.
- A Carotid Ultrasound test usually takes about 30-45mins
- While lying on your back, our cardiac technician will apply a warm gel to your skin above the site of each carotid artery to facilitate the transmission of ultrasound waves back and forth.
- A small ultrasound transducer will be gently pressed against the side of your neck and a live-action image will be recorded. The carotid intimal media thickness will then be measured.
- Your Carotid Ultrasound will be reviewed by our doctor and a summarized report will be provided and explained to you during your review.
How does the doctor use this test to treat me?
Our doctor will explain to you how you can maintain the good results and reduce the risk of development of blockages in your neck arteries.
Depending on the severity of the blockages, our doctor may recommend the following therapies:
a. Lifestyle modifications
- Eating a healthy diet rich in fruits, vegetables, whole-grain breads and cereals with reduction in consumption of food rich in saturated fat.
- Regular exercise
- Maintaining a healthy weight
- Cessation of cigarette smoking
- To lower blood pressure, cholesterol or blood sugar
- To prevent blood clots from developing
c. Carotid revascularization treatments
- Carotid Angioplasty – Implantation of a wire mesh (stent) to open up the blockage and improve blood flow
- Carotid Endarterectomy – Surgical procedure to remove the carotid artery plaques.