Atherosclerosis causes most carotid artery stenosis. In this condition, blood lipids (usually cholesterol), calcium, and other immunocytes build up along the inner layer of the arteries forming plaque. The thickening narrows the arteries and reduces blood flow. If the narrowing of the carotid arteries becomes severe enough to block blood flow, it can result in a stroke. If a piece of plaque breaks off, it can disrupt blood flow to the brain and result in a stroke.

Ultrasound of Carotid Intima-media Thickness (IMT) is a safe, non-invasive, painless examination that without exposure to radiation. It is used to measure the amount of plaque build-up in the walls of the arteries that supply blood to the head. The method is using ultrasound to measure the thickness of the two inner layers of the carotid artery—called the intima and media. If the test shows increased thickness in the inner layers of the carotid artery, patient may be at risk for cardiovascular disease and stroke.

The following risk factors may increase chances of developing carotid artery disease:

• Old age
• High blood pressure
• Diabetes
• Tobacco smoking
• High cholesterol
• Coronary artery disease (CAD)
• Obesity
• Physical inactivity
• Family history of atherosclerosis and/or stroke