SIMULATION OF OPTICAL TOMOGRAPHIC IMAGING

To realize optical-CT imaging, fundamental behavior of light in living bodies is analyzed by use of Monte Carlo method, and a computer simulation of optical-CT imaging is conducted. By tracing the scattering paths of each photon, the microscopic Beer-Lambert law is found to hold even in strongly scattering and weakly absorbing media. Simulation of the optical-CT imaging has utilized this behavior to propose a new data processing method called temporally extrapolated absorbance method. This method is based on the temporally resolved measurement of transmitted light through scattering and absorbing object and reference. The difference in the optical density between the object and the reference evaluated at the shortest time of flight along the incidence line provides line integrals of the difference in the absorption coefficient between the object and the reference. A set of this data is used to reconstruct an image of the difference in the absorption coefficient which has a reasonable accuracy and spatial resolution.