What is CT angiography?
A coronary computed tomography (CT) angiogram is a diagnostic imaging test that uses advanced technology to produce high-resolution, three-dimensional images of the moving heart and its vessels. The scan may be carried out if you've been identified as possessing a high risk for coronary disease. This quick, painless test clearly defines plaque, calcium buildup and narrowed arteries, as well as damaged muscle.
Why it's done
CT angiogram is used to check your heart for various conditions, but primarily it is used to diagnose or exclude the presence of coronary artery disease.
Who it's for
CT angiography is beneficial for patients who have an intermediate risk for heart disease with suspicious cardiac symptoms. It is also commonly recommended for individuals with chest pain and low risk profiles, as well as to those with unclear or inconclusive stress tests and with suspected congenital abnormalities of the coronary arteries.
You will be exposed to a small amount of radiation during the procedure because of the X-ray technology used. This exposure equates roughly to the amount of radiation the average American is exposed to over a three-year period. This amount is usually harmless but excessive radiation exposure has been linked to cancer.
Although reactions are rare, some patients may experience allergic reactions to the dye used for heart definition. If you have a known allergy, alert your doctor and alternative dyes may be used or a combination of steroids can reduce the reaction risk.
Pregnant mothers are advised against CT angiograms because of the risk radiation poses to an unborn child. Nursing mothers should not breastfeed for 24 hours following the procedure.
If you've had previous reactions to the contrast dye or have kidney disease or severe diabetes, you will be advised against the procedure, as your kidneys may not be strong enough to endure the dye.
Some overweight patients are not suitable for the procedure due to limitations of the machinery and equipment. The CT scanner has a fixed dimension and general weight restrictions of 450 pounds.
What to expect
When you arrive at The Heart Institute for a CT angiography, you'll be guided to the radiology department. The CT images are taken within a large box-shaped machine with a hole and a short tunnel that contains a patient examination table. You will lie down on the table while it slides in and out of the tunnel.
So that images aren’t blurred by the motion of your heartbeat, a beta-blocker medication may be administered to momentarily decrease your heart rate. While the scan takes place, you'll be asked to lie very still to ensure the accuracy of images taken of your heart and surrounding tissues.
Your technician will place electrodes on your chest to monitor your heart throughout the test and will talk you through the process via an intercom system. While you are lying on the table, the X-ray tube will move around your chest to capture several angles. You will not see this tube moving, but you will hear a whirring sound.
How to prepare
You will want to arrive at The Heart Institute in comfortable clothing for your procedure. Be sure to remove all metal objects, jewelry and accessories. If your doctor has specified that contrast dye will be used in your procedure, you will be asked not to eat or drink anything immediately beforehand. As the CT angiography test is considered low-risk and noninvasive, you will be capable of driving yourself home after the test and should not experience any discomfort.
Once your CT angiogram is completed you will be able to drive yourself home or, if necessary, immediately return to work. The procedure is generally easy and painless, although some people can find the process slightly stressful or claustrophobic. Your scans will be available shortly after your test is complete and interpreted by a radiologist. Your doctor will go through your results with you and will suggest steps to follow, which may include a follow-up scan, treatment or lifestyle changes.