Coronary Computed Tomography Angiography (CCTA) is a heart imaging test that helps determine if plaque buildup has narrowed a patient’s coronary arteries, the blood vessels that supply the heart. Plaque is made of various substances circulating in the blood, such as fat, cholesterol and calcium that deposit along the inner lining of the arteries. Plaque, which builds up over time, can reduce or in some cases completely block blood flow. Patients undergoing a CCTA scan receive an iodine-containing contrast material (dye) as an intravenous (IV) injection to ensure the best possible images of the heart blood vessels.