与组织微观结构相关的散射参数γ及其测量方法

Scattering Parameter γ Related to Tissue Microstructure and Measuring Method

研究了光源附近微区的漫反射率RΦ与收集孔径Φ、约化散射系数μ′s和散射相函数相关的参数γ之间的关系。根据不同的生物组织,选取不同的散射相函数,采用Monte Carlo模拟方法得到了光子经生物组织后的漫反射率数据,用得到的数据来验证反射率RΦ与无量纲的约化散射系数μ′sΦ之间的关系。结果表明:当μ′sΦ<2时,RΦ对散射相函数的变化是敏感的,且与μ′sΦ呈线性关系,其斜率与γ呈二次函数关系。光源附近微区的漫反射率RΦ对γ的变化是敏感的,这为测量与生物组织微观结构相关的散射参数γ提供了一种较为简单的方法。

The relationship between diffuse reflectance RΦ measured close to the source and parameter γ related to collecting aperture Φ, reduced scattering coefficient μ′s, and scattering phase function is discussed. According to different biological tissues, different scattering phase functions are selected, and the diffuse reflectance data of photons passing through biological tissues are obtained by Monte Carlo simulation. The relationship between the reflectance and dimensionless reduced scattering coefficient , where μ′sΦ<2,RΦ is the collection aperture of scattered light, is validated by the data obtained. It is found that when 2, RΦ is sensitive to the change of the scattering phase function and has a linear relation with μ′sΦ. The slope of is a quadratic function with respect to γ. Results demonstrate that the diffuse reflectance RΦ of the micro-area near the light source is sensitive to the change of γ. This provides a simple method for measuring γ related to the microstructure of biological tissues.