A CT scan uses x-ray
radiation to generate a nice detailed image of the body's internal structures. Sometimes oral and IV contrast are used to help delineate these structures and add
to the radiologist's ability to better define the anatomy and any structural abnormalities.
A CT-A (or CT angiogram) is a CT scan that is done to specifically look at certain blood vessels within the body. Intravenous contrast is administered and the images are taken when the contrast is thought to be passing through the vessels of interest. In the case of a coronary CT-A, the vessels around the heart are the focus of the study.
A coronary CT-A is a relatively non-invasive way of gaining more information about the coronary arteries; it can be used to look at the take-off of the arteries from the aorta, the course of the arteries around the heart, and can help detect the presence of any calcium or cholesterol plaques in the arteries that can signify the presence of coronary artery disease.