Application for myocardial imaging and fundamental experiments were studied using straight chain fatty acid analog IPPA [omega-(p-iodophenyl)-pentadecanoic acid]. Biodistribution of IPPA in rabbits (n = 6) shows the accumulation in liver was maintained 81.0% at 30 minutes, while the accumulations of heart, lungs and kidneys were 30.0%, 10.0% and 15.0% respectively. Especially the accumulation of heart decreased rapidly from 48.0% at 3 minutes to 30.0% at 30 minutes, reflecting the effect of beta oxidation. On the other hand, in the acute myocardial infarction mode (n = 6), with occlusion in left anterior descending coronary artery, all 6 cases showed defect images at the corresponding areas after injection of 3 mCi of IPPA. Myocardial imaging with IPPA should be useful not only for myocardial metabolic diseases (cardiomyopathy etc.) but also for ischemic heart disease.