Optical coherence tomography imaging: current status and future perspectives

Optical coherence tomography (OCT) is an optical analogue of intravascular ultrasound that provides high-resolution (10–20 μm) cross-sectional images of coronary arteries. The micron-scale resolution of OCT has an ability to capture in vivo what was previously seen only through a pathologist’s microscope. OCT can differentiate three types of atherosclerotic plaque components (fibrous, fibrocalcific and lipid-rich) with high sensitivity and specificity. Early in vitro and in vivo studies have demonstrated a possibility of OCT for identifying vulnerable plaque features, in particular the quantification of plaque rupture, intracoronary thrombus, thin-capped fibroatheroma and the distribution of macrophages within the fibrous cap. In addition, OCT has shown its effectiveness in imaging the short-term and long-term results of percutaneous coronary intervention. OCT can precisely assess stent strut malapposition, tissue protrusion, coronary artery dissection, and neointimal hyperplasia following stent implantation. Recently, next-generation OCT, called Fourier-domain OCT, has already been shown to be a powerful enabling technology for coronary imaging. The novel developments with high frame rate and fast pullback speed simplifies procedural requirements and will eventually eliminate limitations of current OCT systems such as need for proximal vessel balloon occlusion during image acquisition. This report details current and future developments in OCT imaging, which include exciting technological advancements that will consolidate the position of OCT as a key diagnostic tool to complement the armamentarium of the cardiologist well into the future.