Cerebral Perfusion Associated With Postural Changes: an ASL MR Perfusion Study

A 1.5 Tesla MRI device with a large magnet bore (70 cm) allowing positions change will be used. Two measures will be performed, one in supine position and the other in head down position (-20°). A 3D FSE ASL sequence will be acquired and CBF maps reconstructed. Volume of interest (VOI) will be placed on cortical grey matter (frontal and posterior gyrus), on subcortical deep grey matter (caudate nuclei, thalami) and subcortical white matter (semi oval centers