Abstract
Images of oxygenation state of living body can be obtained by use of time-resolved near-infrared spectroscopy based on the change in the absorption spectra of hemoglobin or myoglobin. The photon-tissue interaction is analyzed by the Monte Carlo method and the Finite Element method to solve the photon diffusion equation. The absorbance extrapolated temporally to the shortest time of flight are shown to provide a set of projection data for the reconstruction by the filtered back projection. FEM (Finite Element Method) analyses are shown to be flexible to the complex change in the distribution of the optical properties. More sophisticated procedures of the inverse problems are expected to be developed for optical-CT (computed tomography) in the near future.
