Dear Gabriel,
On Mon, 27 Jan 2014 13:22:33 +0000, Gabriel Go.Es. <[log in to unmask]> wrote:
>Hello all,
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>I'm looking for performing lognitudinal analyses on MRI and non-MRI data, but I'm not sure if it is possible to apply all the preprocessing as with VBM8 toolbox to the non-MRI data, this is PET adata.
The segmentation in VBM8 is limited to T1-weighted data. Thus, you cannot apply it to PET data. I would suggest the following steps:
1. realign your PET data using the halfway registration implemented in VBM8
2. create average PET image
3. use average PET image to estimate spatial normalization parameters using PET template
4. apply normalization parameters to all realigned PET data
>
>Also I'm having some troubles with the VBM8 preprocessing on the MRI data, I'm always getting the following error:
>"There is not enough overlap in the images to obtain a solution.
This message means that you probably have a limited field of view and the brain is not fully covered. In that case it is difficult to estimate normalization parameters. You can try to define the origin and roughly correct for rotation according to the template. Then, you might have better starting values. However, if your data are consisting of only a few slices this will be ot working, because information is insufficient to estimate any transformations.
Best,
Christian
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>In both cases, MRI and PET I have cross-sectional data already VBM8 analyzed. I don't know if the preprocessing of this be valuable for any purpose?
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>Many thanks in advanced,
>Gabriel
>
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