The two main types of nuclear heart scans are single photon emission computed tomography (SPECT) and cardiac positron emission tomography (PET).
Single Photon Emission Computed Tomography
Doctors use SPECT to help diagnose coronary heart disease (CHD). Combining SPECT with a stress test can show problems with blood flow to the heart. Sometimes doctors can detect these problems only when the heart is working hard and beating fast.
Doctors also use SPECT to look for areas of damaged or dead heart muscle tissue. These areas might be the result of a previous heart attack or other cause.
SPECT also can show how well the heart's lower left chamber (left ventricle) pumps blood to the body. Weak pumping ability might be the result of a heart attack, heart failure, and other causes.
Tracers commonly used during SPECT include thallium-201, technetium-99m sestamibi (Cardiolite®), and technetium-99m tetrofosmin (Myoview™).
Positron Emission Tomography
Doctors can use PET for the same purposes as SPECT—to diagnose CHD, check for damaged or dead heart muscle tissue, and check the heart's pumping strength.
Compared with SPECT, PET takes a clearer picture through thick layers of tissue (such as abdominal or breast tissue). PET also is better at showing whether CHD is affecting more than one of your heart's blood vessels.
Right now, however, there's no clear advantage of using one scan over the other in all situations. Research into advances in both SPECT and PET is ongoing.
PET uses different tracers than SPECT.