Cardiac CT scanning

What is a Cardiac CT?

A computerized tomography (CT) coronary angiogram is an imaging test that looks at the arteries that supply your heart with blood. Unlike traditional coronary angiograms, this is a non-invasive way to assess the blood supply to the heart.

Instead, a CT coronary angiogram relies on a powerful X-ray machine to produce images of your heart and its blood vessels. They are an increasing common technique to image the blood supply to the heart.

What are the common uses of a cardiac CT?

A cardiac CT is particuarly useful in patients with a relatively low likelihood of coronary artery disease (as a ‘rule out’). In those patient with a high likelihood of coronary artery disease and typical symptoms of angina, a standard ‘invasive’ coronary angiogram may be more appropriate.

How should I prepare for a cardiac CT?

You should wear comfortable, loose-fitting clothing to your exam. You may be given a gown to wear during the procedure.

Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and should be left at home or removed prior to your exam. You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras containing metal underwire. You may be asked to remove any piercings, if possible.

You will be asked not to eat or drink anything for a few hours beforehand, as contrast material will be used in your exam. You should inform your physician of all medications you are taking and if you have any allergies. If you have a known allergy to contrast material, or “dye,” your doctor may prescribe medications (usually a steroid) to reduce the risk of an allergic reaction. These medications generally need to be taken 12 hours prior to administration of contrast material. To avoid unnecessary delays, contact your doctor before the exact time of your exam.

Also inform your doctor of any recent illnesses or other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may increase the risk of an unusual adverse effect.

You may be asked to take beta blocker medication to lower your heart rate a day or two before the examination

Are there any risks?

Cardiac CT scanning is safe, non-invasive procedure. However, it does involve exposure to radiation, which carries a small risk of causing cancer. A contrast dye is also used to obtain the images, and may cause a deterioration in kidney function,