Coronary Calcium Scan
Coronary calcium scans use a special X-ray test called computed tomography (CT) to check for the buildup of calcium in plaque on the walls of the arteries of the heart (coronary arteries). This test is used to check for heart disease in an early stage and to determine how severe it is. Coronary calcium scans are also called cardiac calcium scoring.
The coronary arteries supply blood to the heart. Normally, the coronary arteries do not contain calcium. Calcium in the coronary arteries is a sign of coronary artery disease (CAD).
A CT scan takes pictures of the heart in thin sections. The pictures are recorded in a computer and can be saved for more study or printed out as photographs.
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Why It Is Done
Your doctor may want you to have a coronary calcium scan if you have several risk factors for heart disease. Or your doctor may want you to have this test if he or she thinks that results could change your treatment for heart disease.
This test might be most helpful for people who have no symptoms but who are at medium risk for heart disease. 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. This means that 10 to 20 out of 100 people with this level of risk will have a heart attack in the next 10 years.
To find out your risk, see the Interactive Tool: Are You at Risk for a Heart Attack? And talk with your doctor about your risk for heart disease.
A coronary calcium scan is not advised for routine screening for coronary artery disease.1 This test may not tell your doctor any more about your risk for heart disease than your risk factors do.
This screening test is not for you if:
How To Prepare
You do not need to do anything before you have this test. But you may be asked to not smoke or not eat or drink anything that has caffeine for a few hours before your test.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).
How It Is Done
A coronary calcium scan is usually done by a radiology technologist. The pictures are usually interpreted by a radiologist. Other doctors, such as a family medicine doctor, internist, cardiologist, or surgeon, may also review this test.
You will need to remove any jewelry that might be in the way of the X-ray picture. You may need to take off some of your clothes. If so, you will be given a gown to use during the test. For some CT scans, you may be able to wear your clothes. If so, wear loose clothes that do not have zippers or snaps.
Small metal discs called electrodes will be put on your chest. Wires connect these to an EKG machine that records the electrical activity of your heart on paper. The EKG records when your heart is in the resting stage, which is the best time for the CT scans to be taken.
If your heart rate is 90 beats per minute or higher, you may be given medicine to slow your heart rate.
During the test, you will lie on a table connected to the CT scanner. The scanner is a large doughnut-shaped machine.
The table slides into the round opening of the machine and the scanner moves around your body. The table will move a little every few seconds to take new pictures. You may hear clicking or buzzing sounds as the table and scanner move.
You may be asked to hold your breath for 20 to 30 seconds while pictures of your heart are taken. It is very important to hold completely still while the pictures are taken.
During the test, you are usually alone in the scanner room. But the technologist will watch you through a window. You will be able to talk with the technologist through a two-way intercom.
A coronary calcium scan takes about 30 minutes.
How It Feels
You won't have any pain from the X-rays during the coronary calcium scan. But the table you lie on may feel hard and the room may be cool. You may find it hard to lie in one position for a long time.
The chance of a coronary calcium scan causing a problem is small.
After you have the test, talk with your doctor about your results. The radiologist may discuss initial results with you right after the test.
Your test result is a number that is your calcium score. The score can range from 0 to more than 400. Any score over 100 means that you are likely to have heart disease. The higher your score, the greater your chance of having a heart attack.
People who score between 100 and 400 or higher, and who are at medium risk for heart disease, are more likely to have a heart attack in the next 3 to 5 years than people who score 0.2
What Affects the Test
Reasons you may not be able to have the test or why the results may not be helpful include:
What To Think About
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