Arridge S R, Dehghani H, Schweiger M, Okada E
Department of Computer Science, University College London, England.
Med Phys. 2000 Jan;27(1):252-64. doi: 10.1118/1.598868.
We present a method for handling nonscattering regions within diffusing domains. The method develops from an iterative radiosity-diffusion approach using Green's functions that was computationally slow. Here we present an improved implementation using a finite element method (FEM) that is direct. The fundamental idea is to introduce extra equations into the standard diffusion FEM to represent nondiffusive light propagation across a nonscattering region. By appropriate mesh node ordering the computational time is not much greater than for diffusion alone. We compare results from this method with those from a discrete ordinate transport code, and with Monte Carlo calculations. The agreement is very good, and, in addition, our scheme allows us to easily model time-dependent and frequency domain problems.
我们提出了一种处理扩散域内非散射区域的方法。该方法源自一种使用格林函数的迭代辐射度 - 扩散方法，但其计算速度较慢。在此，我们提出一种使用直接有限元方法（FEM）的改进实现。基本思想是在标准扩散有限元方法中引入额外方程，以表示非散射区域内的非扩散光传播。通过适当的网格节点排序，计算时间比仅进行扩散计算时增加不多。我们将此方法的结果与离散纵标输运代码的结果以及蒙特卡罗计算结果进行了比较。一致性非常好，此外，我们的方案使我们能够轻松地对时域和频域问题进行建模。
