Cardiac CTA is a non-invasive CT that looks at the walls of the coronary arteries which supply blood to the heart. On occasion the arterial walls build up either fatty or calcium deposits (plaque). If untreated the plaque can narrow and decrease the blood flow to the heart muscle thus, causing chest pain and/or a potential heart attack.
Intravenous contrast is administered during the test to highlight the blood vessel to determine whether it flows freely through the coronary arteries. The test can only be performed if the patient does not have a contrast allergy.