Radionuclide ventriculography is often referred to as a MUGA (multiple-gated acquisition) scan. It is a type of nuclear imaging test which shows how well your heart is pumping.

A MUGA scan is a test using a radiopharmaceutical and a special camera to take pictures of your heart as it pumps blood.

  • The test measures how well your heart pumps with every heartbeat.
  • The test is called “multi-gated” because a gamma camera takes pictures at specific times during each heartbeat.
  • The test may be done while you stay still (resting scan), exercise or both.
  • The test measures your ejection fraction, which is the amount of blood pumped out of the heart during each heartbeat (contraction). It’s usually expressed as a percentage. For example, an ejection fraction of 60 percent means that 60 percent of the total amount of blood in the left ventricle when it is full is pumped out with each heartbeat. A normal ejection fraction is between 50 and 75 percent.

During the MUGA scan, a small amount of a radiopharmaceutical is injected into your blood. This radiopharmaceutical attaches to your red blood cells. A gamma camera takes pictures of your heart. This lets doctors 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 performed regularly if you are taking, or about to take, medication that is potentially harmful to your heart muscle such as certain forms of chemotherapy for cancer.


Trinity Medical Imaging