How Does It Work?

During a MUGA scan, a small amount of radioactive tracer is injected into a vein in your arm. The tracer “tags” or “labels” your red blood cells by attaching to them for a few hours.

The tagged red blood cells distribute evenly in your blood. As these cells travel through the heart, the tracer gives off a small amount of radiation that can be detected with a scanning camera. A computer processes the information and produces images that show how radioactivity is distributed in the heart.

The camera is linked to an electrocardiogram (ECG). Your heart’s electrical signals trigger the camera to take a series of pictures at precise moments during the heartbeat cycle. This is called “gating.”

Gating creates images that are sharp and clear. It also produces moving images that show the left and right lower chambers, or ventricles, as they contract and pump blood.

A MUGA scan is usually done while you are at rest. In some cases, it may be done while you exercise.

What Does It Show?