Hi - I would be very cautious about doing this. It might be best to get these ROIs from the structural (e.g. via FIRST) and then apply those to the diffusion data. Cheers. On 2 Dec 2011, at 09:57, KimMJ wrote: > Dear experts, > > I want to analyze between-group comparisons of FA and MD of subcortical deep GM nuclei (i.e., thalamus, caudate, putamen..) using a whole-brain voxel-wise manner like TBSS. > How can I do it? > Should I lower the FA threshold of mean FA skeleton to 0.1 or below (tbss_4_prestats 0.1)? > > Thank you in advance for your help. > > MJ Kim --------------------------------------------------------------------------- Stephen M. Smith, Professor of Biomedical Engineering Associate Director, Oxford University FMRIB Centre FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK +44 (0) 1865 222726 (fax 222717) [log in to unmask] http://www.fmrib.ox.ac.uk/~steve ---------------------------------------------------------------------------