Molecular imaging by MRI.

The goal of molecular imaging is to detect pathologic biomarkers, which can lead to early recognition of diseases, better therapeutic management, and improved monitoring for recurrence. MRI is a particularly attractive method for molecular imaging applications, due to its noninvasive nature, outstanding signal to noise ratio, high spatial resolution, exceptional tissue contrast, and short imaging times. Site-specific MRI contrast agents have been developed to target biologic processes that occur early in the development of atherosclerotic plaques, including angiogenesis and lipid accumulation, or biosignatures that appear later, such as fibrin and tissue factor resulting from plaque rupture. Moreover, targeted contrast agents can also serve as drug delivery vehicles, combining diagnosis and therapy. If ultimately successful, these emerging molecular imaging agents and techniques will allow early disease recognition and quantification prompting therapeutic intervention before serious sequelae ensue.