Like many nuclear medicine procedures, cardiac molecular imaging involves the injection of a radioactive label, or "radiotracer", which circulates into the heart. Using either a PET (positron emission tomography) or SPECT (single photon emission computed tomography) scanner, the patient then undergoes a scan of the heart that detects the radioactive signal from the heart and produces a detailed three-dimensional image.
How does nuclear imaging help people with heart disease?
A nuclear medicine physician can then determine the amount of blood flow (perfusion) that the walls of the heart are receiving, whether the cells in the heart are functional and healthy (viability), and whether the heart has suffered permanent damage from a prior heart attack (myocardial infarction).
When evaluating the blood flow (perfusion) to a patient’s heart, it is very useful to evaluate the blood flow while the heart is working faster and harder (under "stress") and compare the blood flow to when the heart is beating normally (at "rest"). When evaluating the functional (viability) status of the heart, it is not necessary to test the heart under stress.