Comparison of Optical Coherence Elastography and Ultrasound Shear Wave Elastography in Gelatin Tissue-Mimicking Phantoms

Abstract

Underlying biomechanical properties of tissues are important for tissue development, cell migration, wound healing, tumor progression, and numerous other medically relevant tissue states. Because of this, it is important to be able to measure these properties with both precision and accuracy. Elastography is a noninvasive imaging technique that measures a tissue’s response to deformation to assess tissue stiffness. In shear wave elastography, a shear wave is generated in a tissue and the wave speed is analyzed to determine tissue mechanical properties. Two imaging modalities are frequently used for elastography due to their ease of use and high resolution: optical coherence elastography (OCE) and ultrasound shear wave elastography (USE). OCE, which utilizes the near-IR interferometry of optical coherence tomography, benefits from superior axial and lateral resolution and fast acquisition speed but suffers from limited penetration depth due to light attenuation. USE benefits from deeper penetration but doesn’t have the resolution or speed possible with optical imaging. In this work, we compare the results and repeatability of shear wave measurements on gelatin tissue-mimicking phantoms using OCE and USE, and validate these measurements with uniaxial compression testing. We show that although OCE has a higher precision of measurement, both OCE and USE are capable of coming close to the value obtained via uniaxial compression testing. We use Bland-Altman plots to perform repeatability analysis and show that we can reliably identify a 0.13 m/s difference in speed with OCE and a 0.16 m/s difference in speed with USE. Our results show that measurements between OCE and USE are comparable and that either modality may be chosen based upon clinical, tissue, and depth constraints.

Speaker

Justin Rippy
University of Houston
USA

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