You could run FAST to get a grey/white/csf segmentation and then fslstats <segmentation> -l 2 -u 2 -V Peace, Matt. -----Original Message----- From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On Behalf Of Massieh Moayedi Sent: Tuesday, May 12, 2009 12:47 PM To: [log in to unmask] Subject: [FSL] Whole brain GM volume Hello, I was wondering if there was a way of determining the whole brain GM volume for each subject. Thanks, Massih Moayedi