ABSTRACT
This chapter illustrates the use of the Monte Carlo method to model the generation and escape of fluorescence in a tissue with both homogeneous and heterogeneous fluorophore concentrations. The program uses a simple steady-state Monte Carlo subroutine, that launches photons as either a collimated beam of variable beam radius; a focused Gaussian beam with variable beam radius, focal depth, and focal waist radius; or an isotropic point source at a chosen depth. The history of this Monte Carlo simulation began with a Monte Carlo simulation written in 1984 that implemented the Henyey-Greenstein scattering function and a mismatched air/tissue boundary. Monte Carlo simulation is an attractive method for simulating generation and escape of fluorescence in a tissue. A medium often has some uniform background fluorophore concentration. The amount of fluorescence generated in each bin of medium is proportional to the local fluence rate of excitation.
