Coronary calcium scans are done in a hospital or outpatient office. The x-ray machine that's used is called a computed tomography (CT) scanner.
The technician who runs the scanner will clean areas of your chest and apply sticky patches called electrodes. The patches are attached to an EKG (electrocardiogram) machine to record your heart's electrical activity during the scan. This makes it possible to take pictures of your heart when it's relaxed, between beats.
The CT scanner is a large machine that has a hollow, circular tube in the center. You'll lie on your back on a sliding table. The table can move up and down, and it goes inside the tunnel-like machine.
The table will slowly slide into the opening in the machine. Inside the scanner, an x-ray tube moves around your body to take pictures of your heart. The technician controls the CT scanner from the next room. He or she can see you through a glass window and talk to you through a speaker.
You'll be asked to lie still and hold your breath for short periods while each picture is taken. You may be given medicine to slow down a fast heart rate. This helps the machine take better pictures of your heart. The medicine will be given by mouth or injected into a vein.
A coronary calcium scan takes about 10 to 15 minutes, although the actual scanning takes only a few seconds. During the test, the machine makes clicking and whirring sounds as it takes pictures. It causes no discomfort, but the exam room may be chilly to keep the machine working properly.
If you become nervous in enclosed spaces, you may need to take medicine to stay calm. This isn't a problem for most people, because the head will remain outside the opening in the machine.