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Hi, Thank you! I applied one more time fslstats to my images. Indeed, the location of the negative voxels may not be too problematic, but the negative values are of the same range as positive (eg. -31688 and 30531, I did not divide by 3 to get it closer to 10000) and on the origdata histogram I see really nothing below zero, too. I just wonder if I did any basic mistake or something else could have happened. Best wishes, Aga On 25.01.2008 17:47 Uhr, "Steve Smith" <[log in to unmask]> wrote: > Hi, > > I don't think that tbss_1_preproc (at least the version with FSL4) can > create new negative values, but it does multiply the original values > to make them a lot larger, so maybe you started with VERY slightly > negative values that are sufficiently small that you didn't notice > them, and after the rescaling, they were more obvious? It's probably > not a problem anyway if they are around the edge of the brain? > > Cheers, Steve. > > > > On 25 Jan 2008, at 10:36, Agnieszka Burzynska wrote: > >> Dear all, I resend this message, because I still do not know what is >> wrong: >> >> >> Hi, >> I applied tbss_1_preproc to my S0 images. In origdata, none of them >> had >> values below 0, however, after the scaling in the FAi folder there >> are 2 >> cases, in which I see negative values around the brainstem. >> >> How did this happen and what should I do? I thought it is just a >> simple >> mulitiplication by a given number (here by 10). >> >> Thank you and best wishes, >> Aga >> > > > --------------------------------------------------------------------------- > 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 > ---------------------------------------------------------------------------