What do we see in a coronary calcium scan?

A coronary calcium score is based on x-ray technology. An electron beam computed tomography utilizes radiation to detect calcium. Calcium will only develop on atherosclerosis, which is cholesterol buildup. A normal calcium score would be zero, which usually indicates there is no cholesterol. However, a younger person may develop a cholesterol blockage but still have a zero calcium score. A calcium score of one or greater indicates definite atherosclerosis; usually the higher the score, the more extensive the atherosclerosis. If there is a high score, your doctor may recommend further testing.

After a coronary calcium scan, you'll get a calcium score called an Agatston score. The score is based on the amount of calcium found in your coronary (heart) arteries. You may get an Agatston score for each major artery and a total score.

The test is negative if no calcium deposits (calcifications) are found in your arteries. This means your chance of having a heart attack in the next 2 to 5 years is low.

The test is positive if calcifications are found in your arteries. Calcifications are a sign of atherosclerosis and coronary heart disease (CHD). (Atherosclerosis is a condition in which the arteries harden and narrow due to plaque buildup.) The higher your Agatston score is, the more severe the atherosclerosis.

You can use this calculator from the National Heart, Lung, and Blood Institute to see how your Agatston score compares with scores of people of your age and ethnic background.

An Agatston score of 0 is normal. In general, the higher your score, the more likely you are to have CHD. If your score is high, your doctor may recommend more tests.

This answer from the National Heart, Lung and Blood Institute has been reviewed and/or edited by Dr. William D. Knopf.