Dear Carl,
On Tue, 12 Feb 2008 13:33:11 +0000, Carl Johan Ekman <[log in to unmask]> wrote:
>Dear VBM users!
>I have been using the VBM5 toolbox from http://dbm.neuro.uni-jena.de/vbm/
>for preprocessing of images. Now the toolbox has been updated to VBM5.1
>and some changes has been made to the Estimate+Write options. Since only
>the latest version of the toolbox is downloadable I would like to know how
>to perform the same operations in the new version as I have done in the
>old one.
>The changes I have noticed are:
>
>Bias FWHM: Default value changed rom 60mm to 70mm
>Bounding Box: Changed from -78 -112 -50 to -78 -112 -70
>These are easily adjusted.
>
>My questions are:
>
>Is the setting 'Grey Matter: Modulated Normalised' in the old version the
>same as 'Grey Matter: affine+non-linear' in the new one?
Yes, this is the same. The new added option option is the modulation for non-linear terms only.
>
>What are the default settings in VBM5 (old version) for:
>Set Origin: 'Center of mass' or 'Origin from header' ?
'Origin from header' is equivalent to the old option. However, the new 'center of mass" approach
might help in finding a good initial affine registration and only influences the starting estimates.
>Write affine only: 'affine only' or 'warps+affine' ?
>These options are not possible to select in the old version.
'warp+affine' is the old option.
>
>In VBM5 you could choose Bias Corrected: 'SAVE' what is the equivalent in
>the new VBM5.1 version? 'Normalised space: yes'?
>
Yes.
>Are there more changes in the default settings than the ones I have
>noticed?
>
No. Most of these setting are writing options and have no influence on the segmentation itself. The
only important option for estimating the segmentation is the bias FWHM.
Best,
Christian
____________________________________________________________________________
Christian Gaser, Ph.D.
Assistant Professor of Computational Neuroscience
Department of Psychiatry
Friedrich-Schiller-University of Jena
Jahnstrasse 3, D-07743 Jena, Germany
Tel: ++49-3641-934752 Fax: ++49-3641-934755
e-mail: [log in to unmask]
http://dbm.neuro.uni-jena.de
>I would be very grateful for help!
>
>Carl Johan Ekman, MD
>Karolinska Institutet
>Stockholm, Sweden
>===========================================================
=============
|