Applications of delta-P1 and delta-P3 approximations to optical tomography in small imaging volumes

Abstract

Radiative transport in the delta-P1 and delta-P3 approximations with an extrapolated boundary condition combined with the reciprocity was demonstrated providing accurate estimations for optical perturbations by comparing with experimental data in a small volume of a liquid tissue phantom. For an absorbing target submerged in a homogeneous medium with an albedo of 0.75, both approximations estimated the optical perturbation with acceptable accuracy when the depth of the target is larger than 1.5 mm. For a fluorescent target, the two approximations estimated the perturbations with high accuracy for both shallow and deep regions. Therefore, these two approximations combined with the reciprocity were proposed for rapid tomographic image reconstruction in a small volume or superficial tissues.