Key Points

• Cardiac computed tomography (CT) is a painless test that uses an x-ray machine to take clear, detailed pictures of your heart.
• Each picture that the machine takes shows a small slice of the heart. A computer can put the pictures together to make a large picture of the whole heart.
• Because an x-ray machine is used, cardiac CT scans involve radiation. However, the amount of radiation used is small.
• Cardiac CT is a common test for finding and evaluating heart problems, such as aortic aneurysm, aortic dissection, and pericardial disease. Cardiac CT also may be used to find pulmonary embolisms.
• Sometimes cardiac CT scans show early signs of coronary artery disease (CAD), before a person shows any symptoms.
• Your doctor will give you instructions before the cardiac CT. Usually he or she will ask you to avoid drinks with caffeine before the test. You also may be asked not to eat for 4 hours before the test.
• Cardiac CT will take place in a hospital or outpatient office.
• The CT scanner is a large, square machine that has a hollow, circular tube in the middle. You lie on your back on a sliding table that can move up and down and goes inside the scanner.
• Many x rays are taken while you’re in the CT scanner. A computer can put the pictures together to make a large picture of the whole heart. This picture shows the inside of the heart and the structures that surround the heart.
• A cardiac CT scan usually takes about 15 minutes to complete, but getting ready before the scan can take more time.
• Once the cardiac CT scan is done, you’re able to return to your normal activities.
• A doctor who has experience with CT will provide your doctor with the results of your scan. Your doctor will discuss the findings with you.
• Cardiac CT scans are painless. Some people feel side effects from the contrast dye that’s used during the scan. Serious complications are rare.
• Researchers are studying new ways to use cardiac CT.