Optical coherence tomography (OCT) has opened new horizons for intravascular coronary imaging. It utilizes near-infrared light to provide a microscopic insight into the pathology of coronary arteries in vivo. Optical coherence tomography is also capable of identifying the chemical composition of
atherosclerotic plaques and detecting traits of their vulnerability. At present it is the only tool to measure the thickness of the fibrous cap covering the
lipid core of the
atheroma, and thus it is an exceptional modality to detect plaques that are prone to
rupture (thin fibrous cap
atheromas). Moreover, it facilitates distinguishing between plaque
rupture and plaque erosion as a cause of acute intracoronary
thrombosis. Optical coherence tomography is applied to guide angioplasties of coronary lesions and to assess outcomes of
percutaneous coronary interventions broadly. It identifies
stent malapposition, dissections, and
thrombosis with unprecedented precision. Furthermore, OCT helps to monitor vessel healing after stenting. It evaluates the coverage of
stent struts by the
neointima and detects in-
stent neoatherosclerosis. With so much potential, new studies are warranted to determine OCT's clinical impact. The following review presents the technical background, basics of OCT image interpretation, and practical
tips for adequate OCT imaging, and outlines its established and potential clinical application.