Multiple Gated Acquisition, known as MUGA, is a type of nuclear scan that measures the pumping action of the heart. The MUGA test measures how much blood the heart pumps, or "ejects," with each contraction and how quickly that blood is ejected.

Because this test is very accurate for measuring the ejection fraction, it is preferred by some providers. However, MUGA equipment is more scarce and more expensive than echocardiogram equipment. It requires an injection of a radioactive material and is a bit less comfortable for the patient.