Computed tomography (CT) angiography is a noninvasive heart imaging test. It can determine whether fatty deposits or calcium deposits have built up in coronary arteries that supply blood to the heart. Your cardiologist might order CT angiography if you have a family history of cardiac events, diabetes, or high blood pressure or if you smoke or have high cholesterol.
During CT angiography, a 64-slice Toshiba Aquilon Scanner takes an X-ray of the arteries around your heart. The procedure is painless and less invasive than coronary angiogram or cardiac catheterization. Sometimes a contrast dye containing iodine is used to improve the clarity of the image and show whether the arteries have narrowed (a condition known as arterial stenosis). Without the use of a dye, CT angiography can detect calcium deposits in arteries (or atherosclerosis). This approach is known as coronary artery calcium scoring.
During CT angiography, you will wear a hospital gown and lie on a padded table that slides into scanning equipment shaped like a donut. After making yourself comfortable, you will be asked to raise your arms over your head.
If your procedure includes a contrast dye, it will be administered through a vein (intravenously) in your arm. Some patients say they experience a warm sensation throughout their body when the dye is administered. If you have a rapid heart rate or atrial fibrillation, you also may be given a beta blocker to slow the heart rate.
While you are inside the scanning equipment, an X-ray tube will pass over your body. A technician will operate the scanning machine from another room. At certain times during the test, he or she will ask you to be very still so that the images are clear. After each series of images, the scanning table will move slightly forward and the process will be repeated.
After the test, a cardiologist who specializes in cardiac imaging will review your scans and discuss them with your doctor. Your doctor will then discuss the results with you.
Do not eat or drink for 6 hours before the test. The day before the exam, you also must avoid all stimulants, including energy pills or energy drinks, diet pills, or medication for erectile dysfunction. Be sure to ask your doctor if you have questions about your medications.
Jewelry or other metal objects such as hair clips and belts might interfere with the imaging equipment. For this reason, you cannot wear them during the procedure.
Although CT angiography cannot replace a coronary angiogram, it is an excellent way to find out whether your arteries are narrowing with deposits that may lead to future problems.
CT angiography is typically recommended when you:
- Are at high risk for developing coronary heart disease, but have no symptoms
- Are experiencing unusual symptoms that resemble coronary heart disease, even if you are at low risk
- Have inconclusive results from a stress test
Summit Medical Group does not recommend CT angiography if you:
- Are pregnant
- Have had allergic reactions to dyes during medical imaging
- Have unstable blood pressure, pulse, or other vital signs
- Have impaired kidney function
- Are undergoing radiation therapy to treat other conditions
You can resume normal activities, eating, and drinking immediately after your CT angiography; however, if you are given a sedative, you should not drive. Your doctor will inform you if you should make arrangements to have a ride home after the procedure.
After the test, you should drink plenty of fluids to flush the iodine dye out of your system.
Complications are rare but may include an allergic reaction to the contrast material such as a rash or kidney problems. The risk for allergic reaction is more common in patients with diabetes. If you have any concerns about these side effects, be sure to talk with your doctor.
If you have difficulty breathing after CT angiography, seek treatment immediately as it may indicate a more serious allergic reaction.