Cardiac CT can be used to monitor the results of coronary artery bypass grafting or to follow up on abnormal findings from earlier chest x- rays.
The scan usually takes about 15 minutes to complete, but can take more than an hour including preparation time and, if needed, the time to take medicines such as beta blockers to slow your heart rate. Before the test, a contrast dye, often iodine, may be injected into a vein in your arm. This contrast dye highlights your blood vessels and creates clearer pictures. You may feel some discomfort from the needle or, after the contrast dye is injected, you may feel warm briefly or have a temporary metallic taste in your mouth. Talk to your doctor if you are uncomfortable in tight or closed spaces to see if you need medicine to relax you during the test. During the scan, the technician will monitor your heart rate with an electrocardiogram (EKG). You will hear soft buzzing, clicking, or whirring sounds when you are inside the scanner and the scanner is taking pictures. You will be able to hear from and talk to the technician performing the test while you are inside the scanner. The technician may ask you to hold your breath for a few seconds during the test.