Pulse Corticosteroid Therapy and Effect on Brain Water Diffusivity

In daily clinical use, pulse high dosis corticosteroids are used to treat cerebral edema in different pathological situations ( surgery, trauma, tumors...). Dehydration can theorically concern extra-cellular or intracellular water, or both.

The relative proportion of those two components are not known, as well their kinetics.

Diffusion Weighted Imaging ( DWI) is a none invasive and none toxic technique to study those phenomena.We can also study the diffusivity anisotropy not using a Gaussian distribution but rather a non- gaussian one, more close to the reality ( q Space Imaging ).

Finally, we can study the compartment redistribution between slow and rapid water molecules diffusion by bi-exponential decomposition of the diffusion signal, corresponding, theorically, respectively to the intra- and extra-cellular component.

Hypothesis : The high dosis steroid pulse therapy modifies or not the water free diffusion in DWI and qSI ? Is there a modification in the diffusivity of both rapid and slow component ?