There is a very slight risk of cancer, particularly in people younger than 40 years old who undergo multiple CT scans, because the test uses radiation. If you have a known allergy, you may still be able to receive contrast if you receive medicine ahead of time.

In rare instances, some people may have an allergic reaction to the contrast dye. Your doctor or the imaging center may do a blood test to check your kidney function before the exam. In rare cases, the contrast dye may cause damage to the kidneys, particularly in people who have known chronic kidney problems. The technician may ask you to hold your breath for a few seconds during the test.Ĭardiac CT scans have some risks. You will be able to hear from and talk to the technician performing the test while you are inside the scanner. You will hear soft buzzing, clicking, or whirring sounds when you are inside the scanner and the scanner is taking pictures. During the scan, the technician will monitor your heart rate with an electrocardiogram (EKG). Talk to your doctor if you are uncomfortable in tight or closed spaces to see if you need medicine to help you relax during the test. You will lie still on the table, and the table will slide into the scanner. The CT scanner is a large, tunnel-like machine that has a table. You may feel some discomfort from the needle or, after the contrast dye is injected, you may feel a warm flush briefly throughout your body or have a temporary metallic taste in your mouth. This contrast dye highlights your blood vessels and creates clearer pictures. Before the test, a healthcare provider will inject a contrast dye, often iodine-based, into a vein in your arm. However, it can take more than an hour to prepare for the scan, including time to take medicines such as beta blockers to slow your heart rate or nitroglycerin to help dilate your arteries. The scan itself usually takes only about 15 minutes. You may go to a medical imaging facility or a hospital for a cardiac CT scan. This test may also be used to check the results of coronary artery bypass grafting or to follow up on abnormal findings from earlier chest X-rays. This imaging test can help doctors find heart diseases or problems with the heart or blood vessels supplying blood to the heart or the rest of the body. Computers can combine these pictures to create a three-dimensional (3D) model of your whole heart. Cardiac CT scanĪ cardiac computed tomography (CT) scan, also called a 'CAT scan,” is a painless, non-invasive imaging test that uses X-rays to take many detailed pictures of your heart and its blood vessels. Heart imaging tests take pictures of your heart or its arteries or blood vessels to help your doctor see whether there are any problems. Patricia Bandettini, MD, NHLBI Division of Intramural Research

Radio cardiograph