Coronary calcium scans use a special X-ray test called
computed tomography (CT) to check for the buildup of
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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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
To find out your risk, see the
Interactive Tool: Are You at Risk for a Heart Attack?
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:
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.
probably will not have this test if you have had a
coronary artery bypass surgery (CABG), or
angioplasty. Also, the test usually is not for women
who are or might be pregnant.
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?).
A coronary calcium scan is
usually done by a radiology technologist. The pictures are usually interpreted
radiologist. Other doctors, such as a
family medicine doctor,
surgeon, may also review this
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
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
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
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
A coronary calcium scan takes about 30
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
The chance of a coronary calcium scan causing a problem is small.
After you have the test, talk with your doctor
about your results.
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
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
Reasons you may not be able to
have the test or why the results may not be helpful include:
CitationsU.S. Preventive Services Task Force (2009). Using nontraditional risk factors in coronary heart disease risk assessment. Available online: http://www.uspreventiveservicestaskforce.org/uspstf/uspscoronaryhd.htm.Budoff M, et al. (2006). Assessment of coronary artery disease by cardiac computed tomography: A scientific statement from the American Heart Association Committee on Cardiovascular Imaging and Intervention, Council on Cardiovascular Radiology and Intervention, and Committee on Cardiac Imaging, Council on Clinical Cardiology. Circulation, 114(16): 1761–1791.Other Works ConsultedBudoff MJ, et al. (2008). Computed tomography of the heart. In V Fuster et al., eds., Hurst's The Heart, 12th ed., pp. 577–606. New York: McGraw-Hill Medical.Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.Greenland P, et al. (2007). ACCF/AHA 2007 clinical expert consensus document on coronary artery calcium scoring by computed tomography in global cardiovascular risk assessment and in evaluation of patients with chest pain. Circulation, 115(3): 402–426.Greenland P, et al. (2010). 2010 ACCF/AHA guideline for assessment of cardiovascular risk in asymptomatic adults. Journal of the American College of Cardiology, 56(25): e50–e103.Kim KP, et al. (2009). Coronary artery calcification screening: Estimated radiation dose and cancer risk. Archives of Internal Medicine, 169(13): 1188–1194.Taylor AJ, et al. (2010). ACCF/SCCT/ACR/AHA/ASE/ASNC/NASCI/SCAI/SCMR 2010 – Appropriate use criteria for cardiac computed tomography. Journal of the American College of Cardiology, 56(22): 1864–1894.U.S. Preventive Services Task Force (2009). Using nontraditional risk factors in coronary heart disease risk assessment. Available online: http://www.uspreventiveservicestaskforce.org/uspstf/uspscoronaryhd.htm.
April 25, 2011
E. Gregory Thompson, MD - Internal Medicine & George Philippides, MD - Cardiology
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