LUMINESCENCE OPTICAL TOMOGRAPHY OF DENSE SCATTERING MEDIA

Using a set of coupled radiation transport equations, we derive image operators for luminescence optical tomography with which it is possibl e to reconstruct concentration and mean lifetime distribution from inf ormation obtained from de and time-harmonic optical sources. Weight fu nctions and detector readings were computed from analytic solutions of the diffusion equation and from numerical solutions of the transport equation by Monte Carlo methods. Detector readings were also obtained from experiments on vessels containing a balloon filled with dye embed ded in an Intralipid suspension with dye in the background. Image reco nstructions were performed by the conjugate gradient descent method an d the simultaneous algebraic reconstruction technique with a positivit y constraint. A concentration correction was developed in which the re constructed concentration information is used in the mean-lifetime rec onstruction The results show that the target can be accurately located in both the simulated and the experimental cases, but quantitative in accuracies are present. Observed errors include a shadowing effect in regions that have the lowest weight within the inclusion. Application of the concentration correction can significantly improve computationa l efficiency and reduce error in the mean-lifetime reconstructions. (C ) 1997 Optical Society of America.