中文摘要：

扩散方程模型被广泛应用于光学CT图像的重建中，其精确性直接关系到所成图像的质量。为了研究扩散方程模型对近红外光子输运过程描述的精确性及其适用范围，本文应用Monte Carlo（MC）模拟方法，给出了二维组织体光学CT正向问题的数值模拟结果，并与其扩散方程模型的有限元解进行了分析比较。实验结果表明，基于扩散方程的光子传输模型能较为准确地模拟光子在强散射介质中的输运过程，适用于该种光学参数条件下的图像重建研究。

英文摘要：

Diffusion equation model has been used for optical tomography widely, However, the precision of the numerical results based on diffusion equation is directly related to imaging quality. So, the validity scope of this model is needed to study. In this article, numerical results for scattering tissue based on Monte Carlo （MC） algorithm is presented along with some discussions. Experimental results show the consistency between the Finite Element Method （FEM） solution of the diffusion equation and the MC simulation, which proves the validity of the diffusion equation model for the optical tomography reconstruction.