title: Depth-resolved optic axis orientation in multiple layered anisotropic tissues measured with enhanced polarization-sensitive optical coherence tomography (EPS-OCT).
abstract: Enhanced polarization-sensitive optical coherence tomography (EPS-OCT) is a noninvasive cross-sectional imaging technique capable of quantifying with high sensitivity the optically anisotropic properties of fibrous tissues. We present a method to measure the depth-resolved optic axis orientations in superficial and deep regions of multiple-layered form-birefringent tissue. Additionally, the bulk-optic EPS-OCT instrument provides anatomical fiber direction referenced absolutely to the laboratory frame, in contrast with fiber-based PS-OCT instruments which provide relative optic axis orientation measurements. Results presented on ex vivo murine tail tendon and porcine annulus fibrosis indicate that the method iscapable of characterizing depth-resolved fiber direction [ theta(z)], form-birefringence [Deltan(z)], and form-biattenuance [Delta chi(z)] for at least 10 successive lamellae and a depth of 0.52 mm into the intervertebral disc. Noninvasive assessment of optic axis orientation by EPS-OCT provides increased contrast in images of multiple-layered media and may improve the understanding of fibrous tissue ultrastructure and the diseases or traumas that affect fibrous tissues.
authors.forename: Nate
authors.initials: N
authors.lastname: Kemp
authors.forename: Haitham
authors.initials: H
authors.lastname: Zaatari
authors.forename: Jesung
authors.initials: J
authors.lastname: Park
authors.forename: H Grady
authors.initials: HG
authors.lastname: Rylander Iii
authors.forename: Thomas
authors.initials: T
authors.lastname: Milner