Numerical simulation of photon migration in homogeneous and inhomogeneous cylindrical phantoms

Features of the propagation of low-coherent pulse radiation in phantoms of soft biological tissues (blood-perfused tissues of brain, breast, etc.) are described. Results of mathematical simulation of photon migration based on the diffusion approximation to the radiative transfer equation and Monte Carlo statistical testing are compared. It is corroborated that the photon density normalized maximum (PDNM) in relatively homogeneous strongly scattering media moves towards the center of the object under study. In the presence of inhomogeneities, the character of the PDNM motion changes; the absorbing inhomogeneity in a strongly scattering medium shifts the PDNM motion path towards the point symmetric to the center of this inhomogeneity with respect to the center of the object under study. In cases with a scattering inhomogeneity, the PDNM moves towards its center.