Cardiac PET Scan
A cardiac positron emission tomography (PET) scan is a diagnostic test that allows doctors to examine how well your heart and its tissues are functioning. There are machines that combine PET and computed tomography (CT) to show both the structure and the function of your heart simultaneously.
Cardiac PET scans are useful for diagnosing conditions like blockage in your coronary arteries, and for determining how much damage was caused by a heart attack. The test typically takes less than 4 hours and is done as an outpatient procedure. It is very safe.
What happens during a PET scan?
- Heart monitor leads will be taped to your chest.
- A small amount of radiotracer (radioactive material) will be injected into your arm. The radiotracer deposits itself in your organs and tissues, which allows the PET scanner to detect the energy it emits and produce 3D images. The amount of radiation is minimal and very rarely causes an allergic reaction.
- You will be injected with an agent to simulate stress conditions in your heart. This medication is safe.
- Once the radiotracer has had time to move throughout your body, you will lie down on a narrow exam table that will move through a large tunnel (the PET scanner). You must lie still so that the images will be clear.
- The 3D images will show the amount blood flow reaching different areas of your heart and show any scarring caused by previous heart attacks.
- A cardiologist will review the results with you and forward them to your doctor.
What should I do before having a PET scan?
- You must fast before the test. For 12 hours beforehand, you may drink water but no caffeinated beverages; 24 hours before the test, you must not eat or drink anything.
- If you have diabetes, you should talk to your doctor about food and insulin needs, because fasting before your scan can affect your blood sugar levels.
- Talk to your doctor ahead of time about all the medications you are taking. Bring a list of them with you. You should especially avoid taking any theophylline-containing medications for at least 48 hours before your scan.
- Inform your doctor if you are pregnant or nursing because the radiation could be harmful to your baby or nursing infant.
- Tell your doctor if you have a fear of enclosed spaces (claustrophobia). The doctor may give you medicine before the test that will help you relax.
- Your doctor will share the results with you when they become available, which may take 24-72 hours.