Fundamental study on diffuse reflective optical tomography.

We report a simulation study on diffuse reflective optical computed tomography, in which continuous-wave sources and detectors are placed on the plane surface of a semi-infinite body. We adopted a simple Tikhonov regularization in the inverse problem and demonstrated the feasibility of three-dimensional reconstruction of the absorption coefficient change. The spatial resolution of the reconstructed image was shown to be degrading markedly with the depth. The regularization parameter should be chosen appropriately considering the trade-off between the reconstructed image noise and the spatial resolution. We analysed the dependence of the spatial resolution of the reconstructed image on the regularization parameter and the depth, and also the behaviour of the reconstructed image noise on the regularization parameter and the depth.