Characterization of anisotropic tissues using micro air-pulse spatial deformation spreading

Abstract

In this study, we propose to measure the spatial deformation spreading (SDS) produced by an air-pulse on the surface of tissues during the near-field regime of propagation as a metric to characterize degree of anisotropy. Experiments in isotropic tissue-mimicking phantoms and anisotropic chicken tibialis muscle were conducted using an optical coherence tomography system synchronized with a confocal air-pulse stimulation. SDS ratio measured along versus across the direction of fibers in chicken muscle agreed with the wave speed ratio taken at the same directions, demonstrating the capabilities of the air-pulse SDS technique in measuring the elastic anisotropy of transverse isotropic tissues.