Dear SPMers,
I want to use the DARTEL-Toolbox to do a classic TBM-Analysis, i.e. to draw
inference on the Jacobians directly.
My questions are:
1. Are there any DARTEL specific constraints on TBM-approaches? I searched
the whole DARTEL mailing-list archives and couldnīt find a single note on
DARTEL and cross-sectional TBM-approaches.
2. The resulting Flow-Fields (u_rc1*) (and the associated Jacobians) are
composed of the warpings of grey matter and white matter (despite the name).
Am I seeing that right?
3. Does anyone has a SPM5/Nifti compatible script to log-tansform the
Jacobians and is willing to provide it to me? That would spare me a lot of
(silly) work with the imCalc.
4. Applying the u_rc1* DARTEL Flow-Fields to the rc1* or rc2*-Images
,respectively, in the Deformations-Utility leads to strikingly different
warping results than using the "create warped"-tool (no modulation) in the
DARTEL Toolbox. Does anyone has a explanation for that?
The idea was to compose the Flow-Fields and the sn.mat File containing the
affine normalisation to MNI and use the ytoj-Script (kindly provided to the
SPM mailing list by Dana Perantie) subsequently, but now I am sceptical on
the accuracy of the composition using the Deformations-Utility.
5. The ytoj-script somehow gave me the following error anyway:
??? Matrix index is out of range for deletion.
Error in ==> spm_select>update at 604
dr(findstr([filesep filesep],dr)) = [];
Error in ==> spm_select>selector at 461
update(sel,wd)
Error in ==> spm_select at 131
[t,sts] = selector(varargin{:});
The "select a deformation"-window pops up but the program does not proceed.
Is that a known bug?
(My programming skills are close to zero)
6. In order to avoid all that problems I thought of applying the sn.mat File
of the affine transform from DARTEL-Template to MNI to the DARTEL Jacobians
using normalise-write with preserve amount (total). This would still allow
me to present the results in MNI-Space but I am not sure about the approach
and the error I am introducing by doing so.
Sorry, I know that these are quite a lot questions. Anyway, I would be very
grateful for any hints on any of my concerns.
Thanks,
Michel Grothe
Laboratory of Functional Neuroscience, Seville, Spain
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