On 22 May 2007, at 15:54, Matt wrote:
> Matteo,
>
> There are a couple of ways you could do this. If you want to do your
> tractography on the mean data, you could transform all of your
> diffusion
> datasets into a standard space and then average them, run BEDPOST
> on them
> and draw your ROIs and do the tractography. Alternatively, you can
> transform the b0 to standard space and then use the transformation
> matrix to
> transform each tractography individual result into standard space
> after you
> have generated it in each subjects individual diffusion space.
> Then you can
> make an average of these transformed tractography results. This
> second way
> is how we did it for a recent study.
Indeed - I would definitely recommend that option - you can't run
tractography on the group-average FA map!!
Steve.
> You might also be able to use the TBSS
> program for this, but I'm not familiar with that program.
>
> Peace,
>
> Matt.
>
> -----Original Message-----
> From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On
> Behalf
> Of Matteo Pardini
> Sent: Tuesday, May 22, 2007 8:15 AM
> To: [log in to unmask]
> Subject: [FSL] group tractography
>
> Hi all!!
>
> I have a question regarding FDT.
>
> I am running probabilistic tractography on a group of subjects and
> I am
> drawing my tract of interest in each subject separately.
>
> My next objective is now to create a sort of " mean group pathway" for
> this group and I was wondering if it was possible to run FDT on the
> group
> mean FA or if my only option is to I make this " mean group pathway"
> putting together all the tracts I generated from the single subjects?
>
> I tried to run bedpost on my mean_FA using as nodif and struct the
> images
> of the subject I used as target to generate the mean_FA but I
> didn't work
>
> Thanks for any insight on this
>
> Matteo :-)
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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
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