Frequency-domain imaging through heavily scattering media: a comparison of diffusion and Monte Carlo simulations

A semi-analytic diffusion model to describe frequency domain imaging through heavily scattering media has been validated by a quantitative comparison with Monte Carlo simulations and experimental results. Although the model is not an exact solution it can deal with situations where exact analysis fails. The method lends itself to modeling responses from restricted objects and deals with the fact that the object is embedded in a finite medium. The presence of inhomogeneities is accounted for by a two stage propagation of Green's functions from source to object to detector. Using a combined photon flux and photon density term at the object plane to represent the radiance provides the best match to Monte Carlo simulations.