Feasibility of the assessment of cholesterol crystals in human macrophages using micro optical coherence tomography

Abstract

The presence of cholesterol crystals is a hallmark of atherosclerosis, but until recently, such crystals have been considered to be passive components of necrotic plaque cores. Recent studies have demonstrated that phagocytosis of cholesterol crystals by macrophages may actively precipitate plaque progression via an inflammatory pathway, emphasizing the need for methods to study the interaction between macrophages and crystalline cholesterol. In this study, we demonstrate the feasibility of detecting cholesterol in macrophages in situ using Micro-Optical Coherence Tomography (μOCT), an imaging modality we have recently developed with 1-μm resolution. Macrophages containing cholesterol crystals frequently demonstrated highly scattering constituents in their cytoplasm on μOCT imaging, and μOCT was able to evaluate cholesterol crystals in cultured macrophage cells. Our results suggest that μOCT may be useful for the detection and characterization of inflammatory activity associated with cholesterol crystals in the coronary artery. © 2014 Kashiwagi et al.