Atherosclerosis neovascularization and imaging

Neovascularization in atherosclerotic plaques is particularly prominent in complicated lesions, and has been recently identified as a marker of plaque vulnerability. This observation has led to a growing interest in the development of imaging techniques with the ability to visualize and quantify the extent of plaque neovascularization. Such feature may play an important role in identifying those lesions more prone to destabilization and rupture, and in the guidance and monitoring of therapeutic interventions. Several modalities have emerged as potential candidates for imaging neovessels in atherosclerotic lesions. They include magnetic resonance imaging, x-ray computed tomography, positron emission tomography, single photon emission computed tomography, ultrasound, or near-infrared optical imaging. These techniques differ in their achievable spatial and temporal resolution, availability, cost, reproducibility, degree of intrusiveness, capability to image atherosclerotic plaques in various vascular territories and ability to discern different plaque components, specifically the presence of neovessels. Molecular imaging, a rapidly evolving multidisciplinary field devoted to the visualization of specific physiopathologic processes at the cellular or molecular level, appears particularly well suited for this purpose because of its ability to target and visualize individual molecules specific to neoangiogenesis. In this manuscript we will review current evidence on the potential application of the various modalities, with a particular emphasis in molecular imaging.