Luminescence Optical Tomography of Dense Scattering Media

J. Chang et al. (1997)


Using a set of coupled radiation transport equations, image operators are derived for luminescence optical tomography, with which it is possible to reconstruct concentration and mean lifetime distribution from information obtained from DC and time-harmonic optical sources. Weight functions and detector readings were computed from analytic solutions of the diffusion equation and from numerical solutions of the transport equation using Monte Carlo methods. Detector readings were also obtained from experiments on vessels containing a balloon filled with dye embedded in an Intralipid suspension with dye in the background. Image reconstructions were performed using the conjugate gradient descent method and the simultaneous algebraic reconstruction technique, with a positivity constraint. A "concentration correction" was developed, in which the reconstructed concentration information is used in the mean lifetime reconstruction. The results show that the target can be accurately located in both the simulated and experimental cases but quantitative inaccuracies are present. Observed errors include a shadowing effect in regions having the lowest weight within the inclusion. Application of the concentration correction can significantly improve computational efficiency and reduce error of the mean lifetime reconstructions.