Simulating measurements of diffusion across the cell membrane with DEXSY and FEXSY

Here, we use numerical simulations to demonstrate the feasibility of measuring diffusion exchange across the cell membrane using DEXSY (Diffusion Exchange spectroscopy) and compare it with FEXSY (Filter Exchange Spectroscopy). Simulations were carried out using the CAMINO platform, for a range of permeabilities, in a substrate chosen to model nerve tissue. The results of these simulations suggest that both DEXSY and FEXSY are capable of measuring diffusion exchange, over a physiologically meaningful range of permeabilities, and an extended range of permeabilities (0.365 to 2.008 µm/s). These results demonstrate the potential for these techniques to be used to differentiate pathology from normal tissue.