Cardiac CT for Calcium Scoring

A cardiac CT scan for coronary calcium is a non-invasive way of obtaining information about the presence, location and extent of calcified plaque in the coronary arteries—the vessels that supply oxygen-containing blood to the heart muscle. Calcified plaque results when there is a build-up of fat and other substances under the inner layer of the artery. This material can calcify which signals the presence of atherosclerosis, a disease of the vessel wall, also called coronary artery disease (CAD). People with this disease have an increased risk for heart attacks. In addition, over time, progression of plaque build up (CAD) can narrow the arteries or even close off blood flow to the heart. The result may be chest pain, sometimes called “angina,” or a heart attack.

(Left) CT of normal coronary artery.

(Right) Abnormal CT showing calcium in the left coronary artery.
A: sternum
B: rib
C: heart
D: calcium in the coronary artery

Because calcium is a marker of CAD, the amount of calcium detected on a cardiac CT scan is a helpful prognostic tool. The findings on cardiac CT are expressed as a calcium score. Another name for this test is coronary artery calcium scoring: it results in a number reflecting the degree and extent of calcium deposits in the walls of the coronary arteries.

The extent of CAD is graded according to your calcium score:

Calcium Score	Presence of CAD
	No evidence of CAD
	Minimal evidence of CAD
11-100	Mild evidence of CAD
101-400	Moderate evidence of CAD
Over 400	Extensive evidence of CAD

Cardiac calcium scoring is not done very often because a physical exam and other tests often give enough information about your heart. But if you are at medium risk for CAD based on your risk factors, cardiac calcium scoring may give your doctor more information to decide on your risk of CAD. Medium risk means that you have a 10% to 20% chance of having a heart attack in the next 10 years, based on your risk factors. You can be at medium risk and not have any symptoms of heart disease.

Cardiac calcium scoring is not advised for routine screening, because it can show that you may have plaque in your coronary arteries even if you do not have CAD. This is especially true if you have a low risk of CAD.

General Cardiac Tests

A variety of health factors indicate your chance of having a cardiovascular event such as heart attack or stroke.

Age, hereditary factors, high cholesterol, weight, cigarette smoking, blood pressure, exercise history, and diabetes are all important in determining your risk for heart disease.

Blood tests

Heart Disease Tests, Cardiac Catheterization

There are imaging tests, non-invasive and invasive, that may be used in cardiac risk assessment.

Exercise Stress Tests

An Exercise StressTest is a useful tool for detecting coronary artery disease and for evaluating medical therapy and cardiac rehabilitation following myocardial infarction.

Cardiac catheterization

To view blood flow through your heart, your doctor may inject a special dye into your arteries (intravenously).

This is known as an angiogram. The dye is injected into the arteries of the heart through a long, thin, flexible tube (catheter) that is threaded through an artery, usually in the leg, to the arteries in the heart. This procedure is called cardiac catheterization. The dye outlines narrow spots and blockages on the X-ray images. If you have a blockage that requires treatment, a balloon can be pushed through the catheter and inflated to improve the blood flow in your heart. A stent may then be used to keep the dilated artery open.

CT angiography for CAD

CT Scan (Computerized Axial Tomography) consists of many radiographs shot at the same time from different angles. Later, a computer gathers all the images and reconstructs them in only one image, summing up the images obtained from the different angles.