A cardiac computed tomography (CT) scan is an imaging procedure used to view heart and areas associated with it. Areas that a cardiac CT scan captures include the aorta, arteries and veins, as well as the heart muscle and the pericardium. Through a cardiac CT scan, a doctor might be able to diagnose a problem that exists in any of these areas, such as an aneurysm, blood clot or calcium build-up.
Depending on what area of the heart is being monitored, or what type of problem the scan is evaluating, a cardiac CT scan is sometimes known by different names. For example, a CT scan that detects calcium in the arteries is a coronary calcium scan, or a cardiac CT that concentrates on the arteries is known as a CT angiography. In addition, there are different types of cardiac CT scans as well, such as multidetector computed tomography (MDCT) and electron-beam computed tomography (EBCT). In general, these scans refer to the type of scanner used during the procedure.
Before a patient receives a cardiac CT scan, he or she may be injected with a contrast dye as part of the procedure. This dye helps to make the appearance of blood vessels and other structures clearer in the image. The patient is also usually given medication to slow his or her heart rate and to dilate the arteries.
The patient will lie down on a table, which slides into the machine, and keep still while the scanner revolves around his or her body, taking x-rays of the heart. These images are then combined together by a computer to create a three-dimensional image of the heart. The scan itself usually only takes about 15 minutes, although it often takes more time for the medications administered before the procedure to take effect.
Like all CT scans, a cardiac CT scan is a noninvasive procedure that comes with a low number of risks. One risk of the procedure is that a patient might experience an allergic reaction or other side effects from the contrast dye, if the substance is used, although this is a rare occurrence. A CT scan uses x-rays, and does expose the patient to radiation, which is known to cause cancer. In general, the radiation in one CT scan is equal to the amount a normal person would receive in his or her daily life over the course of about three years.