Hybrid method of finite multiplicity scattering and diffusion approximation in optical imaging of biological tissues

摘要

The reflection of light by a semi-infinite biological medium is modeled by using a combination of finite multiplicity scattering and the diffusion approximation employing the Monte Carlo simulation. The solution to the radiative transfer equation (RTE) is represented as a sum of two terms. The first one is backscattered radiation with a scattering order of no greater than N. The second term represents a convolution of the RTE Green function and an effective source function of an order of (N +1). The first term and the effective source are calculated using the Monte Carlo method, and the RTE Green function is obtained in the diffusion approximation. The solution to the problem of light reflection obtained by using the hybrid approach is compared to the results of the Monte Carlo simulation. The finite scattering order N, which provides a relatively high accuracy of the above hybrid method in the optical study of biological media, is estimated with respect to anisotropy factor and albedo of a single scattering event.