Quantitative shear wave imaging optical coherence tomography for noncontact mechanical characterization of myocardium

Shang Wang, Andrew L. Lopez, Yuka Morikawa, Ge Tao, Jiasong Li, Irina V. Larina, James F. Martin, Kirill V. Larin

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

2 Scopus citations

Abstract

Optical coherence elastography (OCE) is an emerging low-coherence imaging technique that provides noninvasive assessment of tissue biomechanics with high spatial resolution. Among various OCE methods, the capability of quantitative measurement of tissue elasticity is of great importance for tissue characterization and pathology detection across different samples. Here we report a quantitative OCE technique, termed quantitative shear wave imaging optical coherence tomography (Q-SWI-OCT), which enables noncontact measurement of tissue Young's modulus based on the ultra-fast imaging of the shear wave propagation inside the sample. A focused air-puff device is used to interrogate the tissue with a low-pressure short-duration air stream that stimulates a localized displacement with the scale at micron level. The propagation of this tissue deformation in the form of shear wave is captured by a phase-sensitive OCT system running with the scan of the M-mode imaging over the path of the wave propagation. The temporal characteristics of the shear wave is quantified based on the cross-correlation of the tissue deformation profiles at all the measurement locations, and linear regression is utilized to fit the data plotted in the domain of time delay versus wave propagation distance. The wave group velocity is thus calculated, which results in the quantitative measurement of the Young's modulus. As the feasibility demonstration, experiments are performed on tissue-mimicking phantoms with different agar concentrations and the quantified elasticity values with Q-SWI-OCT agree well with the uniaxial compression tests. For functional characterization of myocardium with this OCE technique, we perform our pilot experiments on ex vivo mouse cardiac muscle tissues with two studies, including 1) elasticity difference of cardiac muscle under relaxation and contract conditions and 2) mechanical heterogeneity of the heart introduced by the muscle fiber orientation. Our results suggest the potential of using Q-SWI-OCT as an essential tool for nondestructive biomechanical evaluation of myocardium.

Original languageEnglish
Title of host publicationOptical Elastography and Tissue Biomechanics II
EditorsKirill V. Larin, David D. Sampson
ISBN (Electronic)9781628414172
DOIs
StatePublished - 2015
EventOptical Elastography and Tissue Biomechanics II - San Francisco, United States
Duration: 7 Feb 20158 Feb 2015

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume9327
ISSN (Print)1605-7422

Conference

ConferenceOptical Elastography and Tissue Biomechanics II
Country/TerritoryUnited States
CitySan Francisco
Period7/02/158/02/15

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