Forward and inverse calculations for 3D frequency-domain diffuse optical tomography

Publisher Website
Google Scholar
Abstract
A fast iterative imaging algorithm has been developed to examine the potential of diffuse optical tomography (DOT) for clinical imaging. Forward calculations using diffusion theory were used to generate light fluence distributions within highly scattering media such as tissue. A 3D multigrid finite difference algorithm has been employed to solve the complex diffusion equation in the frequency-domain for irregular objects with spatially varying absorption and scattering coefficients. An iteractive inversion scheme has been used to solve for the distribution of interaction coefficients from tomographic measurements of the phase and amplitude of the AC photon density at the surface of the object. The time required to calculate images can be minimized using the multigrid finite difference forward solution along with a Newton-Raphson steepest descent inversion algorithm. The potential of DOT was evaluated using theoretical 3D test objects with various absorption and scattering inhomogeneities from which the phase and amplitude data were calculated from both finite difference and Monte Carlo simulations. Estimates of the resolution and contrast were calculated in order to assess the detectability of biological targets, such as tumors, blood volume changes, or blood oxygenation changes. The 3D nature of these calculations should be beneficial for optimized iterative reconstruction.

This publication has 0 references indexed in Scilit: