Abstract: Atherosclerosis is an inflammatory disease of the arterial walls and represents a significant health problem in developed nations. Described is a targeted Magnetic Resonance Imaging (MRI) contrast agent for in vivo imaging of early stage atherosclerosis. Early plaque development is characterized by the influx of macrophages, which express a class of surface receptors known collectively as the scavenger receptors (SR). The macrophage scavenger receptor class A (SRA) is highly expressed during early atherosclerosis. The macrophage SRA therefore presents itself as an ideal target for labeling of lesion formation. By coupling a known ligand for the scavenger receptor, dextran sulfate, to a MRI contrast agent, early plaque formation can be detected in vivo. Targeted MR contrast agents offer a unique opportunity to visualize early plaque development in vivo with high sensitivity and resolution, allowing or early diagnosis and treatment of atherosclerosis.