Assessing atherosclerotic plaque morphology: comparison of optical coherence tomography and high frequency intravascular ultrasound.

Abstract

Background-OCT can image plaque microstructure at a level of resolution not previously demonstrated with other imaging techniques because it uses infirared light rather than acoustic waves. Objectives-To compare optical coherence tomography (OCT) and intravascular ultrasound (IVUS) imaging of in vitro atherosclerotic plaques. Methods-Segments of abdominal aorta were obtained immediately before postmortem examination. Images of 20 sites from five patients were acquired with OCT (operating at an optical wavelength of 1300 nm which was delivered to the sample through an optical fibre) and a 30 MHz ultrasonic transducer. After imaging, the microstructure of the tissue was assessed by routine histological processing. Results-OCT yielded superior structural information in all plaques examined. The mean (SEM) axial resolution of OCT and IVUS imaging was 16 (1) and 110 (7), respectively, as determined by the point spread function from a mirror. Furthermore, the dynamic range of OCT was 109 dB compared with 43 dB for IVUS imaging. Conclusions-OCT represents a promising new technology for intracoronary imaging because of its high resolution, broad dynamic range, and ability to be delivered through intravascular catheters.

Optical coherent reflectometry: A new technique to guide invasive procedures

“…Unlike sound waves, infrared light is less strongly reflected from calcified tissues and thus OCR can obtain valid information even behind calcified tissues. Furthermore, OCR can achieve about 10 times higher resolution than conventional ultrasound imaging [9].…”

Coronary Plaque Classification With Intravascular Ultrasound Radiofrequency Data Analysis

“…Therefore, the high accuracy of detecting calcified necrosis supports the premise that the AR classification tree developed in the study is suitable to identify key components of plaques that are vulnerable to rupture. Other invasive techniques recently described include optical coherence tomography and near-infrared spectroscopy, 28,29 which are far from being implemented in a clinical environment. Noninvasive techniques, in particular MRI and CT, have gained interest but are limited by their lower resolution.…”

Development of a Free Space, LED Illuminated Spectral-domain Optical Coherence Tomography Setup

“…The integrated product also describes the capability of obtaining multiple reflections from a single sample that has sub-surface layers at varying depths. Now, the objective of low coherence interferometry is to extract this depth-resolved data [9,10] which in this case is achieved by an inverse Fourier Transform. The depth resolved data defines the axial scan of the OCT system.…”