In diffuse florescence tomography (DFT), the radiative transfer equation (RTE) and its P1 approximation, i.e. the diffuse equation (DE), have been used as the forward models. Since the assumptions of the diffusion approximation are not valid in particular regions of biological tissue which are close to the collimated light sources and boundaries, not scattering dominated or having void-like sub-domains, the RTE-based DFT methodology has become a focus of investigation. Therefore, we present a RTE-based featured-data scheme for time-domain DFT, which combines the discrete solidangle- element method and the finite element method to obtain numerical solutions of the Laplace-transformed 2D timedomain RTE, with the natural boundary condition and collimating light source model. The scheme is validated using the measurement data from phantom and in-vivo small-animal experiments compared to the DE-based scheme.
Diffuse optical tomography (DOT) has been increasingly studied in the past decades. In DOT, the radiative transfer
equation (RTE) and its P1 approximation, i.e. the diffuse equation (DE), have been used as the forward models. Since the
DE-based DOT fails where biological tissue has a void-like region and when the source-detector separation is less than 5
mean free pathlengths, as in the situations of small animal imaging, the RTE-based DOT methodology has become a
focus of investigation. Therefore, the complete formalism of the RTE is attracting more and more interest. It is clear that
the quality of the reconstructed image depends strongly on the accuracy of the forward model. In this paper, A FDM was
developed for solving two-dimensional RTE in a 2cm×2cm square homogeneous tissue with two groups of the optical
properties and different schemes of the spatial and solid angle discretization. The results of the FDM are compared with
the MC simulations. It is shown that when the step size of the spatial mesh becomes small, more discretized angle
number is needed.
Acquisition of the optical structures within a biological body is critical to all the diffuse light imaging modalities, such as
diffuse optical tomography (DOT) and fluorescence molecular tomography (FMT). On an assumption of the optical
homogeneity within the organs, it can be cast as a shape-based DOT issue, which aims at simultaneously reconstructing
the boundary-describing parameters and optical properties of the disjoint domains of distinct tissue types. As the first
step to the solution of this issue, we propose here a continuous-wave mode, elliptic-region-based DOT scheme. The
methodology employs the boundary-element-method (BEM) solution to the diffusion equation as the forward model, and
solves a nonlinear inverse issue that seeks an optimal boundary configuration as well as the optical properties to
minimize the residual norm between measured and predicted data. The proposed scheme is validated using simulated
data for a cylindrical geometry embedding two absorption- and scattering-contrasting ellipses at different noise levels.