Alteration of fatty acid oxidation is considered to be a sensitive marker of ischemia and myocardial damage. On the contrary, persistence of glucose utilization is considered as a suitable marker of myocardial viability in the dysfunctional myocardium. While, PET using fluorine-18 labeled fluorodeoxyglucose (FDG) is considered as an accurate means for assessing myocardial viability, FDG-single photon emission computed tomography (SPECT) using ultrahigh-energy collimators can provide similar information as FDG-PET with regard to viability assessment. The role of metabolic imaging for identifying postischemic insult as “ischemic memory imaging” has recently been focused. A number of reports from Japan showed relatively high diagnostic accuracy of iodinated fatty acid analog [123I-labeled beta-methyl iodophenyl pentadecanoic acid (BMIPP)] imaging for detecting coronary patients without prior myocardial infarction. In addition, the recent data indicates BMIPP imaging has a prognostic value when applied in documented or suspected coronary patients. Thus, single-photon metabolic imaging may play a new and important role for assessing myocardial viability, identifying prior ischemia, and assessing the severity in patients with coronary artery disease using a conventional gamma camera.