Hi, Could you please do a bedpostx_datacheck on the directory you are running qboot and copy the output here? Make sure that you name the data and mask files, as data and nodif_brain_mask. Cheers Stam On 30 Jul 2012, at 15:03, SUBSCRIBE FSL Jay wrote: > Hi Stam, > Its the probability mask extracted from the standard H-O atlas > BW > Jay >