Most diagnostic modalities for imaging of atherosclerosis can not provide information on the biology and metabolism of plaque. A number of molecular imaging targets, which were not specific, for atherosclerosis have been identified. We recently developed a novel HDL therapy using apo A-I mimetic peptide (FAMP). HDL therapy was shown to decrease the atherosclerosis plaque burden in a rabbit model. In this study, we explored the potential of FAMP for use in molecular imaging developing plaque lesions in vivo. FAMP was synthesized with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and radiolabeled with 68Ga for noninvasive PET in a WHHL-MI rabbit with atherosclerotic lesions. 68Ga-DOTA-FAMP was dramatically taken up by atherosclerotic tissues in blood vessels and aorta in WHHL rabbit, but not in normal rabbit ( Fig. 1 ). Uptake of 68Ga-DOTA-FAMP was confirmed at 6 h after injection when plasma radioactivity almost disappeared. We also tried using another tracer radiolabeled with 64Cu, but this did not work as well as 68Ga-DOTA-FAMP. In conclusion, we have developed PET imaging with a 68Ga-DOTA-FAMP tracer for observing atherosclerotic plaque. Detection of these plaques, which are prone to rupture, could be clinically important for the prevention of cardiac events.
