Optical Coherence Tomography, Near-Infrared Spectroscopy, and Near-Infrared Fluorescence Molecular Imaging

Intravascular optical coherence tomography (OCT) is a high-resolution imaging technology that employs a bandwidth in the near-infrared spectrum with wavelengths ranging from 1250 to 1350 nm to probe micrometer-scale structures in combination with advanced fiber-optics to create images. The images are created comparing the back-reflected optical signal from the two arms. Compared with intravascular ultrasound (IVUS), OCT offers a 10 times higher image resolution. Early commercially available versions of the technology used time domain (TD) detection, while the second generation systems using Fourier domain (FD) has significantly improved the signal-to-noise ratio and allows high speed pullbacks with faster acquisition. Imaging in acute coronary syndromes (ACS) includes ruptured plaques and histomorphologic features that can be detected by OCT. Near-infrared spectroscopy (NIRS) is widely used in many disciplines to identify the chemical composition of unknown substances. Optical-based imaging using near-infrared fluorescence (NIRF) has evolved to serve as a promising coronary artery-targeted intravascular imaging platform. © 2017 John Wiley & Sons, Ltd.