Dearest gurus of all things Freesurfer, I am looking for a simple way to quantify the amount of CSF, the total volume of brain matter (excluding ventricular space if possible) and, as a check on these two, the total intracranial area. Essentially I need a way to compare how much room there is for the brain to move around and deform. Any ideas on how best to achieve these goals would be most appreciated. Best, Matthew