Hi David,
--- Thomas Nichols <[log in to unmask]> a écrit :
> David,
>
> Hi. I will be using TFCE. Will this matter for the F
> threshold I use?
>
>
> The point of TFCE is that it is *threshold free*, so
> there is no threshold
> involved. However, we have less experience with F
> images than with T
> images. As F images are like the square of T
> images, if you do not get good
> results you may want try changing the TFCE height
> parameter to 1 (from its
> default value of 2; see the --tfce_H option).
>
> Also, this may seem like a simple question, but is
> there a step by step
> > manual explaining how exactly do draw these masks
> (eg from which slice and
> > which FA image/skeleton), and also the fslmaths
> and fslstats commands you
> > indicated?
> > I apologize if these questions are too basic, but
> nobody else at my
> > institution uses FSL for these purposes, and so I
> am in this by myself (and
> > the very helpful FSL list!!).
> >
>
> I'll have to defer to someone else on the mask
> drawing issue...
I think that what Steve meant was for you to use the
significant results after correction for multiple
comparisons to get the mean FA values in these ROI.
The best thing to do is then not to draw them, but
directly to create them from, say, your tfce-corrected
results.
So something like:
fslmaths mytfceresults_max_tfce_tstat1 -thr 0.95 -bin
mask_of_myresults
then
fslmeants -i all_FA_skeletonised -m mask_of_myresults
-o mean_FA_in_my_mask.txt
Hope this helps,
Gwenaelle
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