Fluorescence attenuated by a thick scattering medium: Theory, Simulations and Experiments.

Fluorescence-based imaging has an enormous impact on our understanding of biological systems. However, in vivo fluorescence imaging is greatly influenced by tissue scattering. A better understanding of this dependance can improve the potential of non-invasive in vivo fluorescence imaging. In this paper we present a diffusion model, based on an existing master-slave model, of isotropic point sources imbedded in a scattering slab, representing fluorophores within a tissue. The model was compared to Monte Carlo simulations and measurements of a fluorescent slide measured through tissue-like phantoms with different reduced scattering coefficients (0.5 to 2.5mm -1 ) and thicknesses(0.5 to 5mm). Results show a good correlation between our suggested theory, simulations and experiments; while the fluorescence intensity decays as the slab's scattering and thickness increase, the decay rate decreases as the reduced scattering coefficient increases in a counterintuitive manner, suggesting fewer fluorescence artifacts from deep within the tissue in highly scattering media. This article is protected by copyright. All rights reserved.