Article,
Effect of the scattering delay on time-dependent photon migration in turbid media
(1997)
Abstract
We modified the diffusion approximation of the time-dependent radiative
transfer equation to account for a finite scattering delay time.
Under the usual assumptions of the diffusion approximation, the effect
of the scattering delay leads to a simple renormalization of the
light velocity that appears in the diffusion equation. Accuracy of
the model was evaluated by comparison with Monte Carlo simulations
in the frequency domain for a semi-infinite geometry. A good agreement
is demonstrated for both matched and mismatched boundary conditions
when the distance from the source is sufficiently large. The modified
diffusion model predicts that the neglect of the scattering delay
when the optical properties of the turbid material are derived from
normalized frequency-or time-domain measurements should result in
an underestimation of the absorption coefficient and an overestimation
of the transport coefficient. These observations are consistent with
the published experimental data. (C) 1997 Optical Society of America.
