Noninvasive visualization of myocardial infarction using radionuclides dates back over eighteen years. Edward A. Carr and William H. Beierwaltes were first to report (1962) successful external imaging of myocardial infarcts in dogs and in man using an Anger scintillation camera. They demonstrated that after intravenous administration of 86Rb or l3ICS an infarct was visualized as a "cold spot," while 203Hg-labeled-chlormeridin resulted in a "hot-spot" image of the infarct. Since then, there have been major developmental improvements in avail able radionuclides, scintillation cameras and...