Decoupled fluorescence Monte Carlo model for direct computation of fluorescence in turbid media.

We present a decoupled fluorescence Monte Carlo (dfMC) model for the direct computation of the fluorescence in turbid media. By decoupling the excitation-to-emission conversion and transport process of the fluorescence from the path probability density function and associating the corresponding parameters involving the fluorescence process with the weight function, the dfMC model employs the path histories of the excitation photons and the corresponding new weight function to directly calculate the fluorescence. We verify the model’s accuracy using phantom experiments and compare it with that of the perturbation fluorescence Monte Carlo model. The results indicate that the model is accurate for the direct fluorescence calculation and, thus, has great potential for application in fluorescence-based in vivo tomography.