Radioiodinated beta-methyl phenyl fatty acids as potential tracers for myocardial imaging and metabolism

Since fatty acids provide the majority of myocardial energy requirements under basal conditions, an alteration in the global or regional utilization of these substrates may be an early indicator of myocardial disease. To determine areas of potential clinical utility of fatty acid imaging, we synthesized a radioiodinated modified fatty acid 14-(p-iodophenyl) beta methyltetradecanoic acid IPBMTA, which cannot undergo beta-oxidation. Preliminary biodistribution and imaging studies were performed in animals and man. These studies suggest that radioiodinated beta-methyl phenyl fatty acids localized rapidly in the myocardium and had prolonged myocardial retention time. The long residence time permits the recording of high quality planar and SPECT images.