title: Accurate extraction of optical properties and top layer thickness of two-layered mucosal tissue phantoms from spatially resolved reflectance spectra.
abstract: We are reporting on an experimental investigation of a movable diffuse reflectance spectroscopy system to extract diagnostically relevant optical properties of two-layered tissue phantoms simulating mucosae that are covered with stratified squamous epithelium. The reflectance spectra were measured at multiple sourcedetector separations using two imaging fiber bundles in contact with the phantoms, one with its optical axis perpendicular to the sample surface (perpendicular probe) and the other with its distal end beveled and optical axis tilted at 45 deg (oblique probe). Polystyrene microspheres and purified human hemoglobin were used to make tissue phantoms whose scattering and absorption properties could be well controlled and theoretically predicted. Monte Carlo simulations were used to predict the reflectance spectra for system calibration and an iterative curve fitting that simultaneously extracted the top layer reduced scattering coefficient, thickness, bottom layer reduced scattering coefficient, and hemoglobin concentration of the phantoms. The errors of the recovered parameters ranged from 7% to 20%. The oblique probe showed higher accuracy in the extracted top layer reduced scattering coefficient and thickness than the perpendicular probe. The developed system and data analysis methods provide a feasible tool to quantify the optical properties in vivo.
authors.affiliation: National Taiwan University, Graduate Institute of Biomedical Electronics and Bioinformatics, No. 1 Sec. 4 Roosevelt Road, Taipei 10617, TaiwanbNational Taiwan University, Department of Electrical Engineering, No. 1 Sec. 4 Roosevelt Road, Taipei 10617, Tai.
authors.forename: Kung-Bin
authors.initials: KB
authors.lastname: Sung
authors.affiliation: National Taiwan University, Graduate Institute of Biomedical Electronics and Bioinformatics, No. 1 Sec. 4 Roosevelt Road, Taipei 10617, Taiwan.
authors.forename: Kuang-Wei
authors.initials: KW
authors.lastname: Shih
authors.affiliation: National Taiwan University, Graduate Institute of Biomedical Electronics and Bioinformatics, No. 1 Sec. 4 Roosevelt Road, Taipei 10617, Taiwan.
authors.forename: Fang-Wei
authors.initials: FW
authors.lastname: Hsu
authors.affiliation: National Taiwan University, Graduate Institute of Biomedical Electronics and Bioinformatics, No. 1 Sec. 4 Roosevelt Road, Taipei 10617, Taiwan.
authors.forename: Hong-Po
authors.initials: HP
authors.lastname: Hsieh
authors.affiliation: National Taiwan University, Graduate Institute of Biomedical Electronics and Bioinformatics, No. 1 Sec. 4 Roosevelt Road, Taipei 10617, Taiwan.
authors.forename: Min-Jie
authors.initials: MJ
authors.lastname: Chuang
authors.affiliation: National Taiwan University, Graduate Institute of Biomedical Electronics and Bioinformatics, No. 1 Sec. 4 Roosevelt Road, Taipei 10617, Taiwan.
authors.forename: Yi-Hsien
authors.initials: YH
authors.lastname: Hsiao
authors.affiliation: National Taiwan University, Graduate Institute of Biomedical Electronics and Bioinformatics, No. 1 Sec. 4 Roosevelt Road, Taipei 10617, Taiwan.
authors.forename: Yu-Hui
authors.initials: YH
authors.lastname: Su
authors.affiliation: National Taiwan University, Graduate Institute of Biomedical Electronics and Bioinformatics, No. 1 Sec. 4 Roosevelt Road, Taipei 10617, Taiwan.
authors.forename: Gen-Hao
authors.initials: GH
authors.lastname: Tien
mesh_terms: D004848:Epithelium / Q000737:chemistry; D006454:Hemoglobins / Q000737:chemistry; D006801:Humans; D008863:Microspheres; D008954:Models, Biological; D009010:Monte Carlo Method; D009092:Mucous Membrane / Q000737:chemistry; D019047:Phantoms, Imaging; D011137:Polystyrenes; D013057:Spectrum Analysis / Q000295:instrumentation* / Q000379:methods*
chemical_list: D006454:Hemoglobins; D011137:Polystyrenes