Diffusion theory for light propagation in biological tissue: limitations and adaptations

Diffusion theory is an approximation of the equation of radiative transport, that is used to describe light propagation in turbid media. This approximation is very popular because of its simplicity, possibilities to describe time-resolved light propagation, and for its appeal to physical intuition. However, it has also its restrictions. It is the aim of this contribution to discuss this method, and to evaluate what can be undertaken to avoid the deviations caused by its restrictions, based on results obtained with the equation of radiative transport