What is cardiac CT?
A cardiac CT scan is a non-invasive X-ray based procedure of obtaining information about the location and extent of plaque in the coronary arteries − the vessels that supply blood to the heart wall. Plaque is a build-up of fat and other substances, including calcium, which can, over time, narrow the arteries or even close off blood flow to the heart. The result may be painful angina in the chest or a heart attack. Because calcium is a marker of coronary artery disease, the amount of calcium detected on a cardiac CT scan is a helpful diagnostic tool.
How do I prepare for my cardiac CT?
- Food and drink. On the day of the exam, please do not consume any caffeinated beverages or food (coffee, caffeinated sodas, chocolate, etc.). Do not eat food within the last two hours prior to the exam. You may drink clear, non-caffeinated liquids until you arrive at the scanner.
- Medications. You may take any medication that you usually take, unless otherwise instructed by your physician’s office.
- When to arrive. We ask you to arrive 30 minutes prior to your appointment time. We will ask you a series of questions that will determine whether or not it is safe for you to undergo the CT. Your early arrival will help to ensure that we are able to perform the test efficiently and safely.
- Preparation. An intravenous catheter will be inserted in your arm for intravenous contrast injection. If you have a known contrast allergy or had a reaction to contrast dye, please tell your physician and CT technologist prior to the exam.
- Beta blocker. The image quality of cardiac CT examinations is highly dependent on your heart rate during the scan. The desired heart rate is 50-65 bpm. Your referring physician may prescribe an oral beta blocker for the day prior to and the day of imaging if your heart rate is typically above this level. In addition, the cardiac imaging team may administer an intravenous beta blocker immediately prior to the examination. Please let the technologist know if you have an allergy to beta blockers or if you cannot tolerate them due to asthma or other lung disease.
What will happen during the exam?
- Your CT technologist will bring you into the CT scan room where you will lie down on the scanner table. The technologist will position your body in the middle of the large doughnut-shaped scanner ring, which holds the X-ray tube and an electronic detector. Electrocardiogram leads will be placed on your chest in order to monitor your heartbeat.
- Before beginning the cardiac CT exam, you will be coached in a method to hold your breath.
- The technologist leaves the room, but is in full view and communication with you through the observation window in the adjoining room.
- Initial images will be taken without IV contrast administration. You will usually receive an injection of contrast to allow visualization of the walls and lumen of your arteries
- The scanner does not touch you, nor do you feel the X-rays. It does make some noise and the table you are lying on may move slightly to make adjustments for a better view. It is important for you to lie very still and at various times you will be asked to briefly hold your breath as the picture is taken.
- We use the latest technology, and the capabilities of our state-of-the-art scanners play a key role in tailoring each exam to your specific needs and reducing radiation exposure.
How long with the cardiac CT take and what should I expect after my cardiac CT?
Exams can take up to 90 minutes; the actual scanning takes about 10 minutes.
After your cardiac CT:
- Instructions. You will have no restrictions after the exam and can return to normal activities.
- Exam results. Every exam is interpreted by a cardiac-imaging specialist. Typically, the results of any examination will be available to your doctor within 24 hours. A report will be sent to your physician.
Radiologyinfo.org for Patients
The radiology information resource for patients. RadiologyInfo.org tells you how various X-ray, CT, MRI, ultrasound, radiation therapy and other procedures are performed. It also addresses what you may experience and how to prepare for the exams. The website contains over 200 procedure, exam and disease descriptions covering diagnostic and interventional radiology, nuclear medicine, radiation therapy and radiation safety and is updated frequently with new information. All material on the RadiologyInfo.org website is reviewed and approved by experts in the field of radiology from the ACR and RSNA, as well as other professional radiology organizations.