Probing lactate exchange in Gray Matter via time-dependent DW-MRS

Time-dependent DW-MRS can probe the underlying tissue microstructure. However, it has been previously shown that time-dependent apparent diffusivity and apparent kurtosis exhibit different behaviors for water and intracellular metabolite. These differences may be largely explained by exchange between intra- and extracellular spaces occurring for water. The aim of this work is to measure time-dependent diffusion of lactate which, like water, is present in and exchanges between both compartments, but for which the exchange rate is unknown. Comparison with water and intracellular metabolites indicates that lactate exchange is slow (relative to the probed diffusion times up to 500 ms).