A multigated acquisition (MUGA) scan checks to see if your heart is pumping blood properly. Other names for this test include cardiac blood pooling imaging, nuclear heart scan, nuclear ventriculography, and radionuclide ventriculography. Some people with cancer receiving chemotherapy may need to have this test during their cancer treatment. Survivors of childhood cancer who have had radiation therapy to the chest, spine or upper abdomen; a bone marrow/stem cell transplantation, or chemotherapy with anthracyclines may also need a MUGA scan as part of their follow-up care.

Anthracyclines are a type of chemotherapy that can damage the heart and its ability to pump blood to the rest of your body. Examples of anthracyclines include daunorubicin (Cerubidine, Rubidomycin), doxorubicin (Adriamycin), and epirubicin (Ellence).

Heart damage from chemotherapy can lead to fluid buildup in your body, causing a condition called congestive heart failure (CHF). People with CHF may experience swollen hands and feet, shortness of breath, dizziness, and an irregular heartbeat.

Before starting chemotherapy and throughout your treatment, your doctor may want to perform a MUGA scan. A MUGA scan checks for:

• Your heart’s ability to pump blood to the rest of your body
  
  
• The size of the ventricles (the two lower chambers that hold blood) in the heart
  
  
• Any abnormal movement of blood through the heart

About the procedure

A MUGA scan is much like a computed tomography (CT) scan, and is performed by a nuclear medicine or radiology technician at a hospital. In most cases, the test does not require you to stay in the hospital overnight. During the test, a small amount of a radioactive material, called a tracer, is injected into a vein, usually in your arm. This material is much like a dye and binds to your red blood cells (blood cells that carry oxygen throughout your body), making it easier to see how blood moves through your heart. After you have received the tracer, you will lie on a table and the technician will put a gamma camera (a special camera that uses gamma rays together with a tracer) above you and take pictures of your heart.

Questions to ask your doctor

Before you have a MUGA scan, consider asking your doctor the following questions:

• Why are you recommending this procedure?
  
  
• Who will perform the MUGA scan?
  
  
• What will happen during the procedure?
  
  
• How long will it take?
  
  
• Will I feel any pain during the procedure?
  
  
• What are the risks of having a MUGA scan?
  
  
• What if I don’t have this procedure?
  
  
• When will I find out the results?
  
  
• Who will explain the results to me?
  
  
• If my results are abnormal, what is the next step?
  
  
• Will I have to repeat this test during my treatment?

Conditions that affect the procedure

There are some conditions that can affect the results of your MUGA scan, or may prevent you from having the scan. These include:

• Pregnancy–A MUGA scan involves a small amount of radiation which does not harm you, but may harm a developing baby.
  
  
• A fast, irregular heartbeat
  
  
• Being obese
  
  
• Heart medications, such as digoxin or nitrates
  
  
• Recent nuclear tests, such as bone or thyroid scans
  
  
• Inability to lie flat or still during the test, which causes blurry images

If you have any of these conditions, talk with your doctor before the procedure. Be sure to also tell your doctor about any prescription and nonprescription medications you are taking, because some of them may affect the results of the test.

Preparing for the procedure

Before having a MUGA scan, your doctor will provide you with specific instructions on how to prepare for the test. These may include:

• Not eating or drinking anything for four to six hours before the test
  
  
• Avoiding caffeine and tobacco for four to six hours before the test
  
  
• Wearing comfortable clothing if your test includes exercise

During the procedure

A MUGA scan may take up to two to three hours to complete; however, it may take less time depending on how many pictures are needed. You will be asked to lie on a table beneath the camera, and stickers called electrodes will be placed on your chest to monitor your heart’s electrical impulses during the test. The camera, which is about three feet wide, will then be placed close to your chest. After positioning, the technician will inject the tracer intravenously (IV). You may feel some mild pain when the IV is inserted. As the tracer moves through your bloodstream, the gamma camera will take pictures to see how well the blood is pumping through your body. Many different views will be taken, and each one takes about five minutes. You will be asked to lie very still during the test, because any movement may cause the images to be blurry.

While having a MUGA scan, you may be asked to exercise in between pictures. This helps the doctor see how your heart responds to the stress of exercise. During the test, you may also be asked to take nitroglycerin (multiple brand names; a drug that opens your blood vessels) to see how your heart responds to the medication.

After the procedure

After the MUGA scan, you will be able to leave the examination room right away. You may have to wait in the hospital for the images to be processed, and if they are blurry you may have to repeat the scan. Drink plenty of fluids and urinate frequently for one to two days after your test so that all of the tracer leaves your body.

Results of the procedure

Normal results of the MUGA scan mean that your heart is pumping blood efficiently throughout your body. A result of 45% or higher is normal. An abnormal result can mean blockage in an artery, poor pumping function, heart valve disease, or other disorders. If you have an abnormal result, your doctor may decide to switch treatments or give you a different type of chemotherapy.

More Information

Tests and Procedures

Late Effects of Childhood Cancer (Part II)

Additional Resources

MedlinePlus: Nuclear Ventriculography

Last Updated: April 27, 2009