MUGA Scan

muga60_lgWhat is a MUGA SCAN?

A MUGA Scan is a type of Nuclear Medicine Scan used to take pictures of your heart.  MUGA refers to the program used by the computer to format the pictures. ( MUltiple  Gated Acquisition).  It is also known as a Gated Blood Pool Exam or as an ERNA Exam (Equilibrium RadioNuclide Angiogram)

The MUGA scan is especially useful for assessing the size and  pumping strength of the left ventricle. This is the part of the heart that pumps blood out to the body.  In people with heart failure, for example, the scan images often shows an enlarged and weakened left ventricle.  The ejection fraction is a commonly used term which measures the pumping strength of the heart. The ejection fraction is the proportion of blood that is pumped from the left ventricle (the main pumping chamber) with each heartbeat. A normal ejection fraction is greater than 50 percent. Patients with heart failure often have an ejection fraction of less than 40 percent. The MUGA scan also provides information about heart wall motion. In people who have had a heart attack, for example, the scan images often show poor wall movement in the area of the heart muscle that was damaged and scarred.

There are different reasons why your cardiologist may want you to have a MUGA Scan and these may include:

  • Performed after a heart attack, to assess how much damage was done to the heart muscle.
  • In patients with heart failure and/or heart muscle disease (cardiomyopathy), to evaluate the size and pumping strength of the ventricles.
  • During chemotherapy for cancer, to monitor the ventricles’ pumping strength (some cancer drugs can be harmful to the heart muscle)

Preparation for Test:

If you are scheduled for a MUGA scan, no special preparation is necessary.

Who will be performing my test?

  • An imaging technologist with special training in the use of radioactive drugs (Nuclear Medicine Technologist) will be taking the images of your heart using a machine called a Gamma Camera.

What can I expect?

Check In: Prep

  • Once you have checked in you will be taken into the prep area by one of our Nuclear Medicine Technologists.  They will verify information from your record and explain the procedure to you.
  • An intravenous line (IV Line) will also need to be placed into a vein in your arm or hand.  This is used to administer the radioactive drug used for imaging.  It is required for this procedure or we will not be able to take the pictures of your heart.
  • You will be asked to lift your shirt or blouse and electrocardiograph (ECG) stickers (heart monitoring stickers) will be placed on your chest. These electrodes are attached to cables which link to an ECG machine.  The EKG signal is connected to a computer that uses this information to properly format the pictures
  • You will be given an injection with a drug called Sodium Pyrophosphate.  This will not have any side effects nor will you have any kind of reaction.  This injection attaches itself to your Red Blood Cells.
  • You will be needed to wait about 20 to 30 minutes for the injection to mix evenly in your body.  You will be asked to remain in the injection area but please feel free to use the rest room at any time if needed.
  • When it is time for imaging you will be given an injection with a radioactive tracer called Technetium Pertechnetate.  This tracer attaches itself to the pyrophosphate injection and allows us to take pictures of the blood in the heart as it circulates through the different chambers. There are no side effects or chance of reactions with this injection either.
  • Imaging is accomplished using a special type of radiation detector called a gamma camera.  This detects the injected tracer in the heart muscle and transfers it to a computer.  The computer processes these images into information that the doctor can use to evaluate how efficiently your heart is pumping. (ejection fraction and wall motion mentioned above)
  • You will sit on the imaging chair and bring your arms over your head.  It is very important that at least the left arm be raised above the head. If it is by your side it may prevent some of the tracer in the heart from reaching the detector. We can attempt to do the scan with your arms at your side but this may seriously affect the ability of the cardiologist to properly evaluate your exam.
  • The imager will be positioned close to your chest at about a 45 degree angle.  The electrodes will be connected to an EKG machine that will transfer information about how fast your heart is beating to the imager.
  • The picture takes approximately 15 minutes and it is very important to remain still and not move at all.
  • Once the picture is completed the camera will be positioned above your chest for another image.
  • When this picture is completed your will be allowed to leave.
  • Total Time from check in until completion is normally about 60 – 75 minutes.

What are the risks?

  • In recommending this procedure your doctor has balanced the benefits and risks of the test against the benefits and risks of not proceeding. Your doctor believes there is a benefit of you having an MUGA.
  • There is a small radiation exposure from the radioactive drug, but this is generally no more than you would receive from any other X-Ray procedure such as a CAT Scan or some  X-Ray Procedures.