Positron emission tomography (PET) viability imaging is used to assess how much heart muscle has been damaged by a heart attack or heart disease. This test is used to determine whether a patient may need angiography, cardiac bypass surgery, heart transplant or other procedures.
There are two parts to the viability test. First, a scan is done to measure resting blood flow in the heart. A radioactive tracer (either rubidium-82 or ammonia-13) is injected into your bloodstream and is taken up by the heart. The PET camera detects radiation released by the tracer to produce the images.
Second, a different radioactive tracer containing glucose, fluorodeoxyglucose (FDG), is injected. This tracer is also taken up by the heart. A second scan is performed to show which parts of your heart may have been damaged. The resulting images show how the different parts of your heart use glucose—a sugar that all cells in the body use for energy. Cells that have been damaged or killed by heart disease or a heart attack use little or no glucose. Healthy cells and cells that are recovering from injury use more glucose.
The two sets of PET images are reviewed together.
- A technologist or nurse will explain the test to you, take a brief medical history, and answer any questions you may have.
- A technologist or nurse will insert an intravenous (IV) tube into a vein in each of your arms.
- You will be brought into the scanner room and asked to lie on your back on the table attached to the scanner.
- Adhesive electrodes will be applied to your chest in order to monitor the electrical activity of your heart with an electrocardiogram (ECG). Your blood pressure will also be monitored.
- A small amount of radioactive material (rubidium-82 or ammonia-13) will be given through the IV.
- You will be asked to lie very still with both arms positioned overhead. The PET camera will take pictures of your heart for 25 to 30 minutes.
- Your blood sugar level will be measured. If you have diabetes, a small amount of insulin and glucose will be given through the IV to increase the absorption of glucose in the heart tissue. If you do not have diabetes, you will drink a special sugar drink. You will then wait for approximately 1 hour.
- A small amount of radioactive material (FDG) will be given through the IV and you will wait 45 minutes.
- You will again be asked to lie very still with both arms positioned overhead. The PET camera will take pictures of your heart for another 25 to 30 minutes.
- The nuclear technologist will process the study. The data will be reviewed by a physician. A report will be sent to the doctor(s) involved in your care.
When booking your appointment
- Please inform us if you are claustrophobic, or discuss this with your doctor.
- Please inform us if you are diabetic so that your appointment is scheduled appropriately.
On the day of your test
- For six hours prior to your test: Do not eat or drink anything, except water.
- On the morning of your test: Do not take diuretics. If you are fasting overnight, do not take your oral diabetic medication/insulin.
- Take your other usual medications unless otherwise directed by your physician. Bring all of your medications with you in the original bottles.
After your test
- All medications can be restarted immediately after your test.
- Check in with your Health Card at the Diagnostic Centre window on the first floor. Please arrive 15 minutes early. For more information, see Coming for a Diagnostic Test.
- The cardiac PET viability test takes about 3 hours to complete.
- If you have any questions prior to your cardiac PET viability test, please call 613-696-7000 x14934, Monday to Friday, 7:00 to 16:00.