Photon-transport forward model for imaging in turbid media

A photon-transport forward model for image reconstruction in turbid media i s derived that treats weak inhomogeneities through a Born approximation of the Boltzmann radiative transfer equation. This model can conveniently repl ace the commonly used diffusion approximation in optical tomography. An ana lytical expression of the background Green's function is obtained from the cumulant solution of the Boltzmann equation. Our model provides the correct behavior of photon migration at early times and reduces at long times to t he center-moved diffusion approximation. Numerical comparisons between this model and the standard and center-moved diffusion models are presented. (C ) 2001 Optical Society of America.