A multigated acquisition (MUGA) scan creates video images of the lower chambers of the heart to check whether they are pumping blood properly. It shows any abnormalities in the size of the chambers (called “ventricles”) and in the movement of blood through the heart. Other names for this test include cardiac blood pooling imaging, nuclear heart scan, nuclear ventriculography, and radionuclide ventriculography.
Usually, an echocardiogram is recommended instead of a MUGA scan for people who will be receiving cancer treatments that may damage the heart. An echocardiogram is also more commonly used to find a preexisting heart condition. But some people may need a MUGA scan instead. Doctors also sometimes use MUGA scans as follow-up care to find potential long-term heart side effects, or late effects. Late effects may occur more than 5 years after treatment. Cancer survivors who may need follow-up MUGA scans include:
People who have had radiation therapy to the chest.
People who have had a bone marrow/stem cell transplant or certain types of chemotherapy.
Learn more about the long-term side effects of cancer treatment.
Cancer drugs that can cause heart damage
Some types of chemotherapy, such as anthracyclines, may damage the heart during cancer treatment. Examples include daunorubicin (Cerubidine, Rubidomycin), doxorubicin (Adriamycin), and epirubicin (Ellence). Other drugs used to treat cancer, such as trastuzumab (Herceptin), can also cause heart problems.
Sometimes, heart damage from these drugs can cause congestive heart failure (CHF). CHF occurs when the heart does not pump enough blood to the rest of the body. People with CHF may experience swollen hands and feet, shortness of breath, dizziness, and an irregular heartbeat. Most often, however, the heart damage is mild and only seen on echocardiograms, MUGA scans, or other heart tests.
Who does my MUGA scan?
A MUGA scan is performed in the radiology department of a hospital or at an outpatient imaging center. It is done by a nuclear medicine technologist who has been trained and certified to conduct the test. A radiologist or a nuclear medicine physician oversees the technologist. A radiologist interprets the scan results.
Getting ready for a MUGA scan
When you schedule the scan, you will receive detailed instructions on how to prepare.
What to eat. You may not be able to eat or drink for 4 to 6 hours before the test. You may also be asked to avoid caffeine and tobacco for up to 24 hours before the test.
Topics to discuss. Be prepared to discuss the following topics with your health care team:
All medications you are taking, especially heart medications such as digoxin (multiple brand names) and nitrates, which can affect the test results
Any drug allergies you have, including if you are allergic to barium
Whether you should take your usual medications on the day of the procedure
Any medical conditions you have, including a fast, irregular heartbeat; obesity; and not being able to lie flat or still.
If there is any chance that you are pregnant or if you are breastfeeding. The small amount of radiation used in the test may harm a developing baby or pass through breast milk.
Whether you have had recent nuclear tests, such as bone or thyroid scans.
Any concerns you may have about the test
Insurance, costs, and consent. Before your appointment, ask your insurance provider what costs will be covered. Find out how much of the cost you will have to pay. Once you arrive at the doctor's office or hospital, you will be asked to sign a consent form. This form states that you understand the benefits and risks of the procedure and that you agree to have it.
During the Procedure
How long will it take? The scan may take up to 3 hours to complete. The timing depends on how many pictures are needed.
What should I wear? When you arrive for your MUGA scan, you may need to remove your clothing from the waist up. This includes jewelry or metal objects that could interfere with the scan. You may be asked to wear comfortable clothing if your test includes exercise.
What will happen during the procedure?
The technologist will place stickers called electrodes on your chest to monitor your heart’s electrical activity during the test. He or she will also inject a small amount of a radioactive material into a vein in your arm. The radioactive material is called a tracer. Sometimes the technologist will take a small amount of blood from your arm and mix it with the tracer. Then the technologist will put the mixture back into your body through an intravenous (IV) line inserted directly into a vein.
The tracer is like a dye. It binds to your red blood cells, which carry oxygen throughout your body. It shows how blood moves through your heart. You will feel a small sting from the injection. But you will not be able to feel the tracer move through your body.
The technologist will ask you to lie still on a table and place a special camera above your chest. The camera is about 3 feet wide and uses gamma rays to track the tracer. As the tracer moves through your bloodstream, the camera will take pictures to see how well the blood is pumping through your body. The pictures will be taken from many views, and each one lasts about 5 minutes.
You may be asked to exercise in between pictures. This helps the doctor see how your heart responds to the stress of exercise. The technologist may also ask you to take nitroglycerin to open your blood vessels and see how your heart responds to the medication.
After the procedure
How will I know when the procedure is finished? After the MUGA scan, you will be able to leave the exam room. The technician may ask you to wait in the hospital while the images are processed. If the images are blurry you may have to do the scan again.
What should I expect after returning home? You can expect to return to your normal activities—including driving—immediately after the test. Drink plenty of fluids and urinate frequently for 1 to 2 days after the scan to help the tracer leave your body.
The test monitors the amount of blood pumped out of your ventricles. A result of 50% or higher is considered normal, meaning that your heart is efficiently pumping blood throughout your body. On the other hand, an abnormal result may mean you have a blockage in an artery, poor pumping function, heart valve disease, or another disorder. If you have an abnormal result, your doctor may decide to switch treatments or give you a different type of chemotherapy.
Questions to ask your health care team
Before having a MUGA scan, consider asking these questions:
Why are you recommending this procedure?
Who will perform the scan?
What will happen during the procedure?
How long will it take?
What are the risks and benefits of having a MUGA scan?
Who can I talk to about the cost of this test?
When will I get the results?
Who will explain the results to me?
If my results are abnormal, what is the next step?
Will I need to have this test again during my treatment?