Dear John,
>Hello.
>
>
>
>I have a couple of quick questions on VBM Preprocessing.
>
>
>
>1. What is the interpolation used when the data is normalized? I
>know the voxel size is 2x2x2, but I am not sure what the interpolation
>used is. Is there a recommended interpolation if I wanted to change it?
>
A 2nd degree B-spline interpolation is applied, which is sufficient for
structural data. This is the right interpolation for data if there are no
NaN and Inf values in your data. A higher degree of B-spline interpolation
is only necessary for (not realigned) fMRI data.
>2. We would like to write out to 1x1x1 voxel size. Is the best
>way to do this to just resample the tpm images to 1x1x1?
>
You can save the raw segmented images and apply normalization parameters as
separate step. In this case you can choose your voxel size in the writing
options. Or you can try the VBM5.1 toolbox, which includes this feature:
http://dbm.neuro.uni-jena.de/vbm
Best regards,
Christian
____________________________________________________________________________
Christian Gaser, Ph.D.
Assistant Professor of Computational Neuroscience
Department of Psychiatry
Friedrich-Schiller-University of Jena
Philosophenweg 3, D-07743 Jena, Germany
Tel: ++49-3641-935805 Fax: ++49-3641-935280
e-mail: [log in to unmask]
http://dbm.neuro.uni-jena.de
>
>
>Thanks for your help.
>
>-John West
>
>Imaging Analyst
>
>IU School of Medicine
>
>
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