title: Toward reliable retrieval of functional information of papillary dermis using spatially resolved diffuse reflectance spectroscopy.
abstract: Spatially resolved diffuse reflectance spectroscopy (SRDRS) has been employed to quantify tissue optical properties and its interrogation volume is majorly controlled by the source-to-detector separations (SDSs). To noninvasively quantify properties of dermis, a SRDRS setup that includes SDS shorter than 1 mm is required. It will be demonstrated in this study that Monte Carlo simulations employing the Henyey-Greenstein phase function cannot always precisely predict experimentally measured diffuse reflectance at such short SDSs, and we speculated this could be caused by the non-negligible backward light scattering at short SDSs that cannot be properly modeled by the Henyey-Greenstein phase function. To accurately recover the optical properties and functional information of dermis using SRDRS, we proposed the use of the modified two-layer (MTL) geometry. Monte Carlo simulations and phantom experiment results revealed that the MTL probing geometry was capable of faithfully recovering the optical properties of upper dermis. The capability of the MTL geometry in probing the upper dermis properties was further verified through a swine study, and it was found that the measurement results were reasonably linked to histological findings. Finally, the MTL probe was utilized to study psoriatic lesions. Our results showed that the MTL probe was sensitive to the physiological condition of tissue volumes within the papillary dermis and could be used in studying the physiology of psoriasis.
authors.affiliation: Department of Photonics, National Cheng Kung University, Tainan, 701, Taiwan; These authors contributed equally to this work and should be considered co-first authors.
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Chen
authors.affiliation: Department of Photonics, National Cheng Kung University, Tainan, 701, Taiwan; These authors contributed equally to this work and should be considered co-first authors.
authors.forename: Jun-Yen
authors.initials: JY
authors.lastname: Guo
authors.affiliation: Department of Photonics, National Cheng Kung University, Tainan, 701, Taiwan.
authors.forename: Shih-Yu
authors.initials: SY
authors.lastname: Tzeng
authors.affiliation: Department of Photonics, National Cheng Kung University, Tainan, 701, Taiwan.
authors.forename: Ting-Chun
authors.initials: TC
authors.lastname: Chou
authors.affiliation: Institute of Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan.
authors.forename: Ming-Jen
authors.initials: MJ
authors.lastname: Lin
authors.affiliation: Institute of Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan.
authors.forename: Lynn Ling-Huei
authors.initials: LL
authors.lastname: Huang
authors.affiliation: Department of Dermatology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, 701, Taiwan.
authors.forename: Chao-Chun
authors.initials: CC
authors.lastname: Yang
authors.affiliation: Department of Dermatology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, 701, Taiwan.
authors.forename: Chao-Kai
authors.initials: CK
authors.lastname: Hsu
authors.affiliation: Department of Photonics, National Cheng Kung University, Tainan, 701, Taiwan; Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, 701, Taiwan.
authors.forename: Sheng-Hao
authors.initials: SH
authors.lastname: Tseng
keywords: (170.3660) Light propagation in tissues; (170.5280) Photon migration; (170.7050) Turbid media