Cardiac nuclear imaging uses radioactive materials (tracers) to obtain diagnostic images of the heart and vessels. Testing involves giving a tiny amount of a tracer to a patient. The tracer collects in the heart and gives off gamma rays, which are detected by a gamma camera. Skilled nuclear medicine technologists perform the tests, which are interpreted by experienced Medical College of Wisconsin nuclear medicine physicians.

The two main types of cardiac nuclear imaging tests are: 
  • Multiple Gated Acquisition (MUGA) — measures how much blood the heart pumps or “ejects” with each contraction (the ejection fraction) and how quickly that blood is ejected. 
  • Nuclear medicine stress test (also called myocardial perfusion imaging) — evaluates the coronary arteries by determining changes in blood flow to the heart during exercise. 

Learn more about other heart and vascular diagnostic tests we offer.