Understanding Cardiac CT Scans
Cardiac Computerized Tomography (CT) Scan combines a series of X-ray views to obtain cross-sectional images of the heart. It can be performed without contrast to look for calcium within the blood vessels, an indicator of disease. When performed with intravenous contrast to look at the heart and vessel walls in detail, it is called coronary CT angiography (CTA).
The technology provides detailed images of coronary arteries so abnormalities can be identified without the danger of a more invasive cardiac catheterization.
Cardiac CT is a common test for finding and evaluating:
- Calcium buildup in the walls of coronary arteries: Calcium may be an early sign of coronary heart disease, in which a fatty substance called plaque narrows the coronary arteries and limits blood flow to the heart.
- Coronary heart disease: With intravenous contrast, the cardiac CT scan can highlight coronary arteries to reveal if they are narrowed or blocked.
- Problems with heart function and heart valves
- Problems with the aorta, such as an aneurysm, when a blood vessel bulges out, or dissection, when layers of the aortic wall peel away from each other
- Blood clots in the lungs: A variation of the cardiac CT scan can also reveal pulmonary embolisms, a blockage in a lung artery most often due to a blood clot that has traveled to the lungs from one of the legs.
- Problems in the pulmonary veins
- Pericardial disease: A cardiac CT scan takes clear, detailed pictures of the pericardium, the sac surrounding your heart, and can reveal complications.
During any CT scan, you are briefly exposed to much more radiation than you would encounter during a regular X-ray. By using advanced technology such as the 256-slice scanner, WellStar is able to significantly reduce the radiation dose of these examinations. Although even this lower level of exposure can theoretically raise the risk of cancer, doctors and scientists believe the careful use of CT scans provide enough valuable cardiac information to outweigh the potential risks. The radiation dose of a properly performed cardiac CT scan is also substantially lower than alternative tests such as a nuclear stress test or conventional catheter coronary angiography.
WellStar Resources & Support
WellStar offers cardiac CT scans at Cardiac CT Imaging Center, WellStar Cobb Imaging Center, WellStar Douglas Imaging Center, WellStar Kennestone Hospital and WellStar Cobb Hospital.
WellStar Health System employs an extensive staff of highly trained imaging professionals and technologically advanced CT scanners, ensuring patients of faster examination times with reduced radiation levels.
Cardiac CT Scan Procedure
Before the Procedure
- For a cardiac CT scan, you will be asked not to eat anything for four to eight hours before your test. You may drink water, but you should not drink caffeinated beverages as they can speed up your heart rate.
- You should inform your WellStar physician or radiologist if you believe you might be pregnant, are breastfeeding, have allergies or kidney problems. You should also inform your doctor if you have any implanted medical devices or artificial joints. If you have issues with claustrophobia, you may want to ask your doctor to prescribe a mild sedative prior to the examination.
- If you are taking Metformin-Glucophage®, Glucovance®, Metaglip®, Avandamet® or generics of these medications, you will need to discontinue them at the time of the test. You should refrain from using these medications for 48 hours after the exam and resume them only after your physician has evaluated your renal function and determined it to be normal.
- Your physician might also prescribe a beta-blocker to slow your heart rate to allow a clearer picture of your heart.
- For the examination itself, you should wear loose, comfortable clothing and avoid garments that have zippers, clasps, belts or any other metal fasteners. You will likely be asked to remove any jewelry, wallets, or anything that might interfere with the X-rays of the CT scan
During the Procedure
Most CT scans conducted at a WellStar imaging center are outpatient, and all are painless procedures that should take only a few minutes after preparation.
When you arrive, a WellStar technologist will ask you to fill out a medical history form. Before the test, the technologies will review your history with you and explain details and answer questions about your specific test. You may be asked to change into a gown to remove any metal on your clothing.
If your exam has been ordered with an IV contrast, it will be administered during the exam. Some patients experience a slight burning sensation, a metallic taste in the mouth and a warm flush across the body because of the contrast. These sensations are normal and usually dissipate after a few moments.
For the examination itself, you will lie down on a narrow table that may be equipped with straps, pillows and a headrest to ensure that you do not move during the examination. The table then slides into the CT scanner through the gantry, a doughnut-like opening.
As the X-ray tube rotates around your body, the table slowly moves through the gantry. You will not hear or feel the X-rays, but there may be loud humming, buzzing and clicking sounds from inside the machine during the procedure.
You need to remain as still as possible because movement can blur the images. Throughout the procedure, you will be able to talk to the technologist in case you need help or feel uncomfortable.
When the exam is finished, you are taken out of the machine, and the intravenous line is removed.
After the Procedure
Once you have completed a CT scan, you may resume most of your normal, everyday activities. There should be no recovery time unless you needed sedation or a contrast for the exam. In that case, you may be asked to remain a short time after the exam to ensure you feel well. You will likely be instructed to drink lots of fluid to help your kidneys remove the contrast material from your body.