Legend. Detection of atherosclerotic plaques by radiolabeled CD68-Fc. (A) Oxidized lipoproteins initiate inflammation and generate foam cells. (B) Scavenger receptors uptake lipoproteins into macrophages. (C) A soluble dimeric form of the scavenger receptor CD68 conjugated to an Fc-fragment was radiolabeled with ¹²⁴I to detect atherosclerosis. Activity of ¹²⁴ICD68-Fc in aortic arch nuclear images was enhanced in ApoE^-/- compared to wild type mice (lower panel) and correlated with plaque extension by sudan red staining (upper panel). See page 7.