Targeted imaging of myocardial damage.

Molecular imaging agents can be targeted to a specific receptor or protein on the cardiomyocyte surface, or to enzymes released into the interstitial space, such as cathepsins, matrix metalloproteinases and myeloperoxidase. Molecular imaging of the myocardium, however, requires the imaging agent to be small, sensitive (nanomolar levels or better), and able to gain access to the interstitial space. Several novel agents that fulfill these criteria have been used for targeted molecular imaging applications in the myocardium. Magnetic resonance, fluorescence, and single-photon emission CT have been used to image the molecular signals generated by these agents. The use of targeted imaging agents in the myocardium has the potential to provide valuable insights into the pathophysiology of myocardial injury and to facilitate the development of novel therapeutic strategies.