Abstract

We developed a finite difference algorithm for the solution of the transport equation, that use the method of discrete ordinates for the angular discretization of the phase function. This code calculates accurately and fast the light distribution in highly scattering media. While this method for solving the transport equation for arbitrary media was introduced as early as 1950 [1] and finds wide range applications in various fields that deal with the transport equation [e.g. 2,3], it has, surprisingly, not been used to describe photon migration in tissues. In biomedical optics the diffusion approximation to the transport equation is often applied [4]. However, the accuracy of the diffusion approximation has yet to be proven for heterogeneous biological media with large gradients in the diffusion coefficient. In this study we compare analytical solutions of the diffusion theory for photon migration in heterogeneous media to calculations based on a finite difference implementation of the transport equation.

© 1996 IEEE