Abstract
Diffuse optical tomography (DOT) is a key technique for evaluating a tumor location and for obtaining muscle function imaging. DOT algorithm consists of the forward model and inverse analysis. The forward model calculates light transmittance in biological tissue at given optical properties. In the inverse analysis, optical properties are evaluated by minimizing a difference between measured profiles and calculated profiles of light transmittance. Recently, the Radiative Transfer Equation (RTE), which is an accurate forward model, has been applied to DOT. However, DOT based on the RTE requires high computational loads, resulting in the application to small animals. To overcome the difficulty, we propose an efficient technique to calculate light transmittance by combining a numerical solution with an analytical solution of the RTE. The proposed technique has the following two steps: 1) light transmittance is numerically calculated in initial values of the optical properties. 2) a variation of light transmittance in change of the optical properties is calculated using an approximation based on the analytical solution. To confirm a validity of the proposed technique, we investigate the variations of light transmittance in a two-dimensional homogeneous scattering medium with the optical properties of human muscle. We can show the variations calclulated from the proposed technique agree will those from the RTE. Thess results indicate the usefulness of the proposed technique for the forward model of DOT.
