Dear Patricia, Did you use the 1mm version of the Harvard-Oxford Atlas or the 2mm version? It would be easiest and best to use the 1mm version. All the best, Mark On 7 Jun 2011, at 14:07, SUBSCRIBE FSL Patricia Pires wrote: > Dear FSL experts, > > is it appropriate to use a mask of Structural Cortical Harvard-Oxford Atlas on an image size of FMRIB58_FA_1mm.nii.gz? I tried to analyze a randomise process with a medial frontal cortex mask of this atlas but it seems bigger and I wonder if dimmensions are appropriate for this type of image. > > Thanks for your help. > > Patricia. >