A Multi-Gated Acquisition Scan (MUGA) scan, also known as Radionuclide Ventriculography (RNV), Radionuclide Angiography (RNA) or gated blood pool imaging, is a non-invasive nuclear imaging test used to measure the ejection fraction (EF) within your heart. EF is the capacity of the ventricle (lower chamber of your heart) to pump blood with each heartbeat. In this test, a minute amount of radioactive tracer is injected into your vein. A special gamma camera along with the use of a computer creates moving images of the heart that detects size, EF and wall motion of the heart.

A MUGA may be used to detect or monitor Congestive Heart Failure (CHF). Oncologists may use this test to look for pre-existing heart conditions or to estimate the effects of chemotherapy on the heart.