Hi - the problem with this is that when you are trying to find the
"most typical" subject you would normally not consider linear changes
as interesting - hence if you are only doing affine registration then
this registration isn't going to tell you anything useful about which
is the most typical subject.....
One option to do what you want would be to use TBSS (including
nonlinear reg) just to find the most typical subject, and then go
back and use FLIRT only.
Cheers, Steve.
On 22 Sep 2006, at 16:07, Katherine Perdue wrote:
> Hello-
>
> I would like to align FA volumes from patients as accurately as
> possible.
> One approach would to be determine a study-specific target - the
> subject in
> the group which is the "most typical". I have found the
> registration tools
> as part of the TBSS stream, but would really like to stay with a
> linear
> transformation.
>
> Is there a way to calculate the overall transformation done between 2
> volumes during a linear transformation (6 dof)? I found the rmsdiff
> function
> but that doesn't seem to be doing quite the right thing, as I want
> to be
> able to put in one transformation matrix and find out how large of a
> transformation was necessary.
>
> Or, do you have other suggestions for linear alignment of FA images?
>
> Thanks,
> Katherine
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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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