Optical Coherence Tomography in Coronary Artery Disease: Toward Sub cellular Imaging

Intracoronary optical coherence tomography (OCT) is an interferometric imaging technology that uses near?infrared light to provide cross?sectional images with an axial resolution of 10 ?m and a transverse of 20?40 ?m in vivo. The imaging capabilities of OCT have enabled visualization of important features of coronary plaque, including thrombus, macrophage, neovascularization, stent implantation and stent strut coverage, which have provided new insights for better understanding of this disease. Frequency domain (FD)?OCT is secondgeneration form of OCT that is able to acquire OCT images at a much higher frame. The high?speed imaging capabilities of FD?OCT have made intravascular OCT practical and the introduction of this new technology is expected to help cardiologists make more informed decisions on coronary interventions. Recently, a new form of OCT, termed micro?optical coherence tomography (?OCT), has been developed, which affords a ten?times spatial resolution improvement compared conventional OCT systems. ?OCT has shown to be capable of imaging sub cellular features of coronary artery that are relevant to atherosclerosis, including leukocyte adhesion and diapedesis, fibrin and platelet accumulation, and individual macrophages, smooth muscle cells, and cholesterol crystals. In addition, ?OCT is capable of evaluating stent struts and the body’s reaction to implantable devices in much greater detail than previously possible. These unique capabilities of ?OCT could make it a useful tool for understanding and diagnosing coronary artery disease at the cellular level.