中文摘要：

采用Monte Carlo方法，研究了生物组织的二阶和三阶光学参量对空间分辨漫反射率R（ρ）的影响。当光源与探测器间距离ρ为几个输运平均自由程l1时，漫射近似理论不再适用，R（ρ）与散射相函数的高阶Legendre矩有关。研究表明：二阶光学参量γ对R（ρ）的影响范围约为5l1，在0．6l1〈ρ〈5l1范围内，R（ρ）随γ减小而降低；三阶光学参量δ对R（ρ）的影响范围约为2l1在0．3l1〈ρ〈2l1内，R（ρ）随占增加而降低；并且当不满足△δ〈△γ的条件时，δ对R（ρ）的影响会补偿γ的影响，使R（ρ）与γ的关系变得无规律。

英文摘要：

Influences of the second-order and third-order parameters of biological tissue on the spatially resolved diffuse reflectance are studied with Monte Carlo simulation. The reflectance R（ρ） is dependent on high-order moments of the tissues for a short source-detector separation, so the diffusion approximation theory fails to describe accurately R （ρ）. It is found that the effective region of second-order parameter γ is about 5l1 （transport mean free path） ,and the curve of the reflectance R（ρ） rises with γ in the region of 0.6l1 〈 ρ〈5l1. The effects of third-order parameter δ on the reflectance R （ρ） are studied, and the effective region is about 2l1. We find that the curves of the reflectance R （ρ） depresses with δ in the region of 0. 3l1〈ρ〈2l1,and the effect of γ on RMC（ρ） appears irregular because that the effect of γ be counteracted by the effect of δ when the condition of Δδ〈〈 Δγ is not satisfied.