Does Heart Test Involve Radiation?

Q. My husband and I each had a test to determine our coronary artery calcium scores. Our cardiologist suggested it.
I would like to know if the large high-pitched machine that hovered over me for some time used radiation. If so, how much did I get?
A. The coronary artery calcium (CAC) score is a relatively new tool to detect plaque in arteries of the heart. The machine you heard used X-rays to take multiple pictures of your chest. The amount of radiation from such a CT scan can vary enormously from one facility to another (Archives of Internal Medicine, July 13, 2009). Your doctor should have told you the range of radiation you may have received.
The value of the CAC score is still being debated (Journal of the American Medical Association, April 28, 2010). It is unclear whether knowing your CAC score will reduce your risk of developing angina or experiencing a heart attack.
There is growing recognition that radiation doses from CT scans may be higher than previously stated (Archives of Internal Medicine, Dec. 14, 2009). Experts are concerned that unnecessary CT scans may raise the risk of cancer.