Fluorescence lifetime imaging in turbid media

The lifetime of a fluorophore generally varies in different environments, making the molecule a sensitive indicator of tissue oxygenation, pH, and glucose. However, Lifetime measurements are complicated when the fluorophore is embedded in an optically thick, highly scattering medium such as human tissue. We formulate the inverse problem for fluorescence lifetime tomography using diffuse photon density waves, and we demonstrate the technique by deriving spatial images of heterogeneous fluorophore distribution and Lifetime, using simulated measurements in heterogeneous turbid media. (C) 1996 Optical Society of America