Nuclear Cardiology is a non invasive imaging technique that demonstrates a highly reliable assessment of myocardial perfusion and function. It can effectively evaluate cardiac status at all stages of coronary disease by utilizing sophisticated gamma camera equipment that measures coronary blood flow from the uptake of an intravenous injection of radioactive isotope localized in the myocardium. Patients will undergo imaging before and after stressing of the heart. Stress tests are performed by either exercise on a treadmill or use of a pharmacological stress agent. Quantitative and semi-quantitative imaging measurements of myocardial uptake are compared between rest and stress to accurately diagnose obstructive coronary disease, risk stratify and evaluate prognosis. The extent of inducible myocardial ischemia evaluated with these imaging techniques has become an important prognostic indicator, markedly facilitating informed therapeutic decisions. The functional assessment acquired can define the subset of patients most appropriate for coronary arteriography and/or myocardial revascularization.