This study aims at emphasizing the effects of reflective boundary conditions (BC) on direct imaging with the help of simulation of radiative transfer in dense media lighted by laser beams. The direct method is based on the formation of an image whose contrast is determined by a combination of the asymptotic logarithmic regime back-scattered slopes obtained at locations distributed on the sample surface. It is found that the asymptotic logarithmic regime is strongly dependent on the frontier reflectivity. As may be expected from physics, reflecting BC damage the image directly obtained as the longer path of the photons tends to blur the contrast.