Molecular vascular imaging represents a novel tool that promises to change the current medical paradigm of 'see and treat' to a 'detect and prevent' strategy. Nanoparticle agents, such as superparamagnetic nanoparticles and perfluorocarbon nanoparticle emulsions, have been developed for noninvasive imaging, particularly for magnetic resonance imaging. Designed to target specific epitopes in tissues, these agents are beginning to enter clinical trials for cardiovascular applications. The delivery of local therapy with these nanoparticles, using mechanisms such as contact-facilitated drug delivery, is in the advanced stages of preclinical research. Ultimately, combined diagnostic and therapeutic nanoparticle formulations may allow patients to be characterized noninvasively and segmented to receive custom-tailored therapy. This review focuses on recent developments of nanoparticle technologies with an emphasis on cardiovascular applications of magnetic resonance imaging.