Quantification in time-domain diffuse optical tomography using Mellin-Laplace transforms

Simulations and phantom measurements are used to evaluate the ability of time domain diffuse optical tomography using Mellin-Laplace transforms to quantify the absorption perturbation of centimetric objects immersed at depth 1-2 cm in turbid media. We find that the estimated absorption coefficient varies almost linearly with the absorption change in the range of 0-0.15 cm(-1) but is underestimated by a factor that depends on the inclusion depth (similar to 2, 3 and 6 for depths of 1.0, 1.5 and 2.0 cm respectively). For larger absorption changes, the variation is sublinear with similar to 20% decrease for delta mu(a) = 0.37 cm(-1). By contrast, constraining the absorption change to the actual volume of the inclusion may considerably improve the accuracy and linearity of the reconstructed absorption. (C) 2016 Optical Society of America