Intravascular Polarimetry: Clinical Translation and Future Applications of Catheter-Based Polarization Sensitive Optical Frequency Domain Imaging.

Kenichiro Otsuka,Martin Villiger,Brett E Bouma,Seemantini K Nadkarni

doi:10.3389/fcvm.2020.00146

Abstract

Optical coherence tomography (OCT) and optical frequency domain imaging (OFDI) visualize the coronary artery wall and plaque morphology in great detail. The advent of these high-resolution intracoronary imaging modalities has propelled our understanding of coronary atherosclerosis and provided enhanced guidance for percutaneous coronary intervention. Yet, the lack of contrast between distinct tissue types and plaque compositions impedes further elucidation of the complex mechanisms that contribute to acute coronary syndrome (ACS) and hinders the prospective identification of plaques susceptible to rupture. Intravascular polarimetry with polarization-sensitive OFDI measures polarization properties of the coronary arterial wall using conventional intravascular imaging catheters. The quantitative polarization metrics display notable image contrast between several relevant coronary plaque microstructures that are difficult to identify with conventional OCT and OFDI. Tissues rich in collagen and smooth muscle cells exhibit birefringence, while lipid and macrophages cause depolarization. In this review, we describe the basic principles of intravascular polarimetry, discuss the interpretation of the polarization signatures, and outline promising avenues for future research and clinical implications.

Highlights

Coronary artery disease is a chronic inflammatory disease that in its most fatal complication provokes acute coronary syndrome (ACS) and in the long term leads to heart failure, causing immense disease burden, and economic cost worldwide [1,2,3]
In a focal analysis of the thinnest part of the fibrous caps, we found that depolarization correlated positively with normalized standard deviation, a metric based on the reflection intensity signal that has been shown to indicate macrophage accumulation [69,70,71]
Intravascular polarimetry (IVP) is an extension of conventional optical coherence tomography (OCT) that measures polarization properties of the coronary arterial wall through standard commercial imaging catheters and without altering the imaging procedure

Summary

Introduction

Coronary artery disease is a chronic inflammatory disease that in its most fatal complication provokes acute coronary syndrome (ACS) and in the long term leads to heart failure, causing immense disease burden, and economic cost worldwide [1,2,3]. Intravascular polarimetry (IVP) with PS-OCT measures the depth-dependent polarization state of the light scattered by tissue and provides spatially resolved maps of tissue birefringence and depolarization [34,35,36]. IVP provides quantitative metrics of tissue polarization properties measured through conventional intravascular imaging catheters.

Results

Conclusion