Time resolved fluorescence imaging in diffuse media

We discuss the application of time domain fluorescence techniques to the recovery of targets embedded in several cm thick biological tissue. Considering the general time domain problem first, a singular value analysis is used to study the optimal use of multiple frequency components extracted from time domain data. Furthermore, a computationally efficient algorithm is presented to tomographically reconstruct fluorophore locations using their decay amplitudes and validated using phantom experiments. The reconstruction algorithm presented here has wide applicability for non-invasive, diagnostic fluorescence imaging in small animals and other biological systems, given that fluorescence lifetime is a sensitive indicator of local tissue environment and elementary interactions at the molecular level.