Permeability and Surface Area of Cell Membranes from the DWI Signal

Dmitry S. Novikov¹, Jens H. Jensen¹, Joseph A. Helpern¹

Diffusion of water in tissues is strongly restricted on the cellular length scale. The consequence of such a restriction is a ubiquitous non-Gaussian shape of the diffusion-weighted imaging (DWI) signal. We demonstrate how a non-Gaussian shape of the DWI signal can originate solely due to the presence of cell membranes, with no diffusivity difference between the intra- and extra-cellular compartments. We find that the effective diffusivity acquires frequency dependence. We relate the cell membrane permeability and surface-to-volume ratio to experimentally relevant parameters, such as dispersive diffusivity and time-dependent kurtosis.