title: Polarized light spatial frequency domain imaging for non-destructive quantification of soft tissue fibrous structures.
abstract: The measurement of soft tissue fiber orientation is fundamental to pathophysiology and biomechanical function in a multitude of biomedical applications. However, many existing techniques for quantifying fiber structure rely on transmitted light, limiting general applicability and often requiring tissue processing. Herein, we present a novel wide-field reflectance-based imaging modality, which combines polarized light imaging (PLI) and spatial frequency domain imaging (SFDI) to rapidly quantify preferred fiber orientation on soft collagenous tissues. PLI utilizes the polarization dependent scattering property of fibers to determine preferred fiber orientation; SFDI imaging at high spatial frequency is introduced to reject the highly diffuse photons and to control imaging depth. As a result, photons scattered from the superficial layer of a multi-layered sample are highlighted. Thus, fiber orientation quantification can be achieved for the superficial layer with optical sectioning. We demonstrated on aortic heart valve leaflet that, at spatial frequency of f = 1mm(-1) , the diffuse background can be effectively rejected and the imaging depth can be limited, thus improving quantification accuracy.
authors.affiliation: Biophotonics Laboratory, Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, 78712, USA.
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.affiliation: Center for Cardiovascular Simulation, Institute for Computational Sciences and Engineering and the Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, 78712, USA.
authors.forename: John
authors.initials: J
authors.lastname: Lesicko
authors.affiliation: Biophotonics Laboratory, Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, 78712, USA.
authors.forename: Manu
authors.initials: M
authors.lastname: Sharma
authors.affiliation: Center for Cardiovascular Simulation, Institute for Computational Sciences and Engineering and the Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, 78712, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Hill
authors.affiliation: Center for Cardiovascular Simulation, Institute for Computational Sciences and Engineering and the Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, 78712, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Sacks
authors.affiliation: Biophotonics Laboratory, Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, 78712, USA.
authors.forename: James W
authors.initials: JW
authors.lastname: Tunnell
keywords: (110.0113) Imaging through turbid media; (170.0110) Imaging systems; (170.6935) Tissue characterization; (290.5855) Scattering, polarization