Radionuclide Angiography (MUGA Scan)
What is a MUGA scan?
Radionuclide ventriculography or radionuclide angiography is often referred to as a MUGA (multiple-gated acquisition) scan. It’s a type of nuclear imaging test. This scan measures your ejection fraction, which shows how well your heart is functioning.
Why do people have a MUGA scan?
Your health care professional may want to check how well your heart pumps blood. A MUGA scan helps your health care team learn more about why you may be having symptoms of poor or reduced heart function.
- Chest pain (angina)
- Trouble breathing
- Dizziness
- Tiredness
Your health care professional may use this scan if other tests, such as an electrocardiogram (ECG or EKG) showed you may have a heart problem. It will show how much blood the heart pumps with each beat. Your heart may not be pumping enough blood to meet your body’s needs. This is called heart failure.
During the MUGA scan, a small amount of a radioactive substance or tracer (called a radionuclide) is put into your blood. The tracer attaches to your red blood cells. A gamma camera takes pictures of your heart. This lets your health care team see the blood inside your heart’s pumping chambers (ventricles). The pictures are taken at the same time during each heartbeat (ECG-gated). A computer analyzes the pictures. The pictures show if areas of your heart muscle aren’t contracting normally and show how well your heart pumps blood. These tests are often done while you’re resting and exercising. A exercise stress test gives your health care team a better idea of how well your heart handles work. It helps them decide the kind and level of exercise right for you.
What are the risks of a MUGA scan?
The radioactive substance you receive is safe for most people. Your body will get rid of it through your kidneys within about 24 hours. If you’re pregnant or think you might be pregnant, or if you’re a nursing mother, don’t have this test. It could harm your baby.
How do I get ready for my test?
- For a “resting” scan, you may be asked avoid drinks containing alcohol or caffeine, such as coffee, tea or soft drinks, for several hours before the test.
- For an “exercise” scan, don’t eat or drink anything except water for four hours before your test. Wear comfortable, loose-fitting clothing and comfortable shoes.
- Your health care professional will explain any changes in your medicine you may need to make to prepare for the scan.
What happens during my MUGA scan?
- Specially trained technicians usually perform the scan in hospitals or clinics.
- During the scan, the technician places small metal disks (electrodes) on your chest, arms and legs. The disks have wires that hook to an electrocardiograph machine to record your ECG. The ECG tracks your heartbeat during the test.
- An intravenous line (IV) is put into a vein in your arm. You are given the radionuclide through the IV line. For a “resting” scan, you will lie on a table with a special camera above it. The camera will take pictures of your heart while you’re resting.
- For an “exercise” scan, you will generally walk on a treadmill or ride a stationary bicycle until you reach your peak activity level. Then, you’ll stop and again lie on a table while the gamma camera takes pictures of your heart. In some labs you may lie on a table and pedal a specially mounted bicycle. As you pedal, the camera will take pictures of your heart.
- The tests take one to two hours.
What happens after a MUGA scan?
- You can usually go back to your normal activities right away.
- You should drink plenty of water to flush the radioactive material from your body.
- The health care professional who sent you for the test will get a written report of the test results. Then, you will have an appointment to discuss the results and next steps.
