Enhanced time-resolved imaging with a diffusion model of photon transport.

Imaging through highly scattering media with transmitted photons with the shortest flight times is limited ultimately by the available number of photons with sufficiently short paths. A method is described that enhances the performance of the time-resolved imaging technique. A least-squares fit was obtained between the measured temporal distributions of transmitted light and a model of photon transport based on the diffusion approximation to the radiative transfer theory. Images constructed from the model estimates of short-path-length photon intensities provide information on internal structure, with a significantly improved signal-to-noise ratio compared with those that would be obtained directly from the data.