Molecular and cellular imaging in cardiovascular disease

Molecular imaging has traditionally been performed with nuclear or optical imaging techniques due to their extremely high sensitivity. However, over the last 1-2 decades, molecular magnetic resonance imaging (MRI) has emerged as a highly feasible and accurate alternative. Many molecular targets of interest in the cardiovascular system are abundantly expressed and can be imaged using conventional gadolinium chelates. More sparsely expressed targets can be imaged with targeted nanoparticles, which have far higher magnetic relaxivities. The use of 19-fluorine to label cells can be performed, in conjunction with proton MRI, on conventional magnetic resonance scanners. In addition, recently developed manganese-based probes may provide an alternative to gadolinium, and chemical exchange saturation transfer (CEST) imaging may allow molecular targeting to be performed without any exogenous contrast agents. The combination of therapeutic and diagnostic effects (theranostics) is an area of intense interest and is being actively explored in the cardiovascular arena.