Particular features of time-dependent diffusion models applied in optical methods for medical diagnostics

In the presented work the absorption coefficient and reduced scattering coefficient of the homogeneous tissue-like biological phantoms are determined using three various types of the diffusion model (classical, refined and extrapolated) in the case of the scattering slab geometry which is commonly used for the optical mammography. The nonlinear relationships of the scattering and absorption coefficients from the slab thickness were obtained for each of the examined models. We suggest that this effect was originated by the inadequate approximation of the scattering phase function features employed in the diffusion models. This interpretation was confirmed by Monte Carlo simulations, where almost the similar type relationships were obtained.