IMAGING OF ARTERIOSCLEROSIS AND THROMBOSIS

Over the past decade several groups have used radiolabeled low density lipoprotein (LDP) in order the investigate liver LDL receptor function on the basis of LDL kinetic studies, and also to demonstrate LDL uptake in human atherosclerotic lesions. The influx of radiolabeled LDL into the vessel wall has allowed visualization of some active forms of atherosclerotic plaques. We could visualize atherosclerotic plaques over 48 hours after injection of autologous111In-labelled LDL. The highest uptake of111In-LDL was found at 2 hours after injection for both the carotid and femoral artery plaques. The kinetic pattern of LDL uptake by the vessel wall could be an indicator for the integrity of endothelial lining: deendothelialized arterial segments seem to retain the maximum of radioactivity. We also found that plaques enriched with foam cells take up 123I-LDL/111In-LDL. In a further approach we have investigated111In- LDL liver uptake in normolipemic subjects and in patients with heterozygous familial hypercholesterolemia (FH). In these studies, FH patients were shown to possess a decreased accumulation of LDL in the liver due to LDL receptor deficiency.