Intima-Media Thickness
What is an IMT Exam?

The carotid IMT test is one tool used by the cardiologists in the preventive cardiology clinic to assess atherosclerosis (hardening of the arteries) in the main blood vessels of the body.

IMT is a new test for the early detection and management of atherosclerosis that is recognized by the American Heart Association.

IMT measures the thickness of the inner most layer of the carotid artery. Increased thickness, even without plaque, correlates with a higher risk of heart attack and stroke. Plaque build-up and thickness can be followed over time to
assess the effectiveness of diet, exercise and medications in treating the disease.

Preparing for the Test:

What to Expect During the Exam:

The technician will place a cool gel on the ultrasound probe before taking images of the insides of your carotid arteries on each side of your neck. There may be some mild pressure, but it will not be painful.

You will not need to disrobe, and will not be exposed to any radiation. The procedure will take about 10 minutes to complete.

After the test is over you may resume your normal activities.


There are no risks associated with the test.

Test Results:

Test results will be discussed with you by your doctor at your next appointment. The technician cannot discuss any interpretations with you at the time of testing.

The Test Background:

35-40% of people who die of heart attack or stroke have no symptoms prior to the event.

An IMT exam is not currently covered by insurance, but is relatively inexpensive.

It has been documented in over 100 studies as being effective in determining the risk for heart attack and stroke, and in assessing the effectiveness of preventative therapies.

Detection of plaque in the carotid artery can help predict the presence of plaque in the coronary arteries.

Soft plaques can rupture and cause blood clots which lead to heart attacks and strokes.

Finding these plaques helps predict the risk of bad outcomes, and the need for further cardiovascular testing or medication therapy.

Further Reading

What is a Heart Attack? American Heart Association

Warning Signs of
Heart Attack?
American Heart Association

Warning Signs of Stroke? American Heart Association

Heart Disease and Stroke? American Heart Association