title: Boundary conditions for light propagation in diffusive media with nonscattering regions
abstract: The diffusion approximation proves to be valid for light propagation in highly scattering media, but it breaks down in the presence of nonscattering regions. We present a compact expression of the boundary conditions for diffusive media with nonscattering regions, taking into account small-index mismatch. Results from an integral method based on the extinction theorem boundary condition are contrasted with both Monte Carlo and finite-element-method simulations, and a study of its limit of validity is presented. These procedures are illustrated by considering the case of the cerebro-spinal fluid in the brain, for which we demonstrate that for practical situations in light diffusion, these boundary conditions yield accurate results.
authors.affiliation: Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Campus de Cantoblanco, Spain. jripoll@icmm.csic.es
authors.initials: J
authors.lastname: Ripoll
authors.initials: M
authors.lastname: Nieto-Vesperinas
authors.initials: SR
authors.lastname: Arridge
authors.initials: H
authors.lastname: Dehghani