Fig. 10: OCT for quantitative coronary atherosclerosis imaging.

Vulnerable plaque features identified by optical coherence tomography (OCT). The panels on the right of the OCT cross-sectional images are graphic representations of the vessel components. a, A fibrous plaque is shown by homogeneous, signal-rich backscattering regions (asterisk). b, The presence of attached thrombus (arrows) overlying a visually intact plaque indicates plaque erosion. c, A lipid-rich plaque (arrows) can be visualized as low-intensity regions with diffuse borders and high-intensity overlying bands. d, One or more regions of calcium protruding into the lumen (arrows) is representative of a calcified nodule. e, Plaque rupture (arrow) can be observed as fibrous cap discontinuity and cavity formation within the plaque. f, Plaque with layers of different optical densities (arrows) is shown. g, The presence of a neoatherosclerosis in-stent plaque rupture is shown by a low-intensity region with diffuse borders and within the stent. h, A thin-cap fibroatheroma (arrow) can be visualized as a plaque with lipid-rich content and a fibrous cap <65–70 μm. i, Longitudinal view and cross-sections below showing different plaque components (lipid-rich plaque, macrophages, thin-cap fibroatheroma, thrombus and ruptured plaque; see arrows in the respective panels) along the left coronary artery. Macrophages are seen as a high-intensity confluent region with a signal intensity exceeding that of background noise (middle panel). Thrombus is seen as a high-intensity backscattering mass protruding into the lumen (middle-right panel).