An analytic scheme for time-domain diffuse fluorescence tomography in circular geometry: methodology and validation

Near-infrared fluorescence diffuse optical tomography has proven to be an efficient tool for visualizing the bio-distributions of fluorescent markers in tissue. We present a two-dimensional image reconstruction method for time-domain fluorescence diffuse optical tomography on a turbid medium of circular domain. The methodology is based on a linear generalized pulse spectrum technique that employs the analytical solution to the Laplace-transformed time-domain photon-diffusion equation to construct a Born normalized inverse model. A pair of real domain transform-factors is introduced to simultaneously reconstruct the fluorescent yield and lifetime images and the resultant linear inversions are solved using an algebraic reconstruction technique. The algorithm is validated using simulated data, and the spatial resolution, noise-robustness and so on are assessed. The experimental validation is performed using a multi-channel time-correlated single-photon-counting system and a cylinder phantom that embeds a fluorescent target made from 1%-Intralipid solution and Cy5.5 agent. The results show that the approach retrieves the position and shape of the target with a reasonable accuracy.