A computerized tomography (CT) scan is a type of X-ray that uses a computer to make cross-sectional images of the body.
CT angiography combines a CT scan with an injection of special dye to produce pictures of blood vessels and tissues in a part of your body. The dye is injected through an intravenous (IV) line started in the arm or hand. Cardiac CTA focuses on producing images of the heart’s structure and function, including valves and chambers.
Reasons for CT Angiography
CT angiography may be used if you have an abnormality that involves the blood vessels in any part of the body — including the brain, heart, lungs, kidneys or other parts of the body. Doctors may use the information from this test to learn more about your condition or to plan treatment. Information from a CT angiogram may help prevent a stroke or a heart attack.
Some reasons to have a CT angiogram include:
- To find an aneurysm (a blood vessel that has become enlarged and may be in danger of rupturing)
- To find blood vessels that have become narrowed by atherosclerosis (fatty material that forms plaques in the walls of arteries)
- To find abnormal blood vessel formations inside your brain
- To identify blood vessels damaged by injury
- To find blood clots that may have formed in your leg veins and traveled into your lungs (pulmonary embolism)
- To evaluate a tumor that is fed by blood vessels
CT coronary angiography specifically looks at the blood vessels that supply the heart. It is a highly accurate method of detecting plaque caused by cholesterol deposits. The plaque can cause narrowing of the heart vessels and lead to chest pain or "angina." It can even cause heart attacks. Together these conditions are labeled as coronary artery disease. By detecting plaque at an early stage, CT coronary angiography helps with the early start of preventive medical therapy — particularly statins — which lower cholesterol, decrease or prevent plaque progression and reduce the chance of heart attacks.
CT coronary angiography is completely noninvasive — no incisions needed. It can replace the need to perform cardiac catheterizations that require inserting a tube through an artery in your leg, arm or neck and threading it through to your heart. CT coronary angiography offers a safe, rapid and convenient method of assessing blockage in the blood vessels of the heart — with no post-procedure restrictions or downtime.
What to Expect
CT coronary angiography is performed after injecting an intravenous dye through the arms. The dye illuminates the blood vessels of the heart, and the CT scanner captures the images of the blood vessels in a few seconds. For a good quality heart scan, your heart rate needs to be around 60 beats per minute, so you may need to take an oral medication to bring the heart rate down.
Just prior to scanning, a dissolvable nitroglycerine tablet is placed under your tongue to increase the size of the blood vessels and make them readily visible under the scanner.
Who Should Have a CT Coronary Angiography
You provider may order a CT coronary angiogram if you have coronary artery disease symptoms, but are not known to have plaque or narrowing of the heart vessels by a prior heart catheterization or chest CT.
The decision to perform CT coronary angiography should be made in the right clinical context and should be solely decided on the basis of a full assessment by your physician.
There are few risks associated with a CT coronary angiogram. Some patients may not be able to have CT coronary angiography, particularly if they have impaired kidney function or an inability to take nitroglycerine or medications that lower your heart rate. If you have a known allergy to intravenous dye, you will need to pre-medicate to prevent contrast-mediated allergy.
Learn more about other heart and vascular diagnostic tests we offer.