Hi Aslýhan,
>
>Hi all SPM' ers
>I am writting from Gazi Ýnstitution. I am a SPM beginner.
>I am planing to compare GMV(grey matter volumes) of 7-12 years old patients
>with age matched healty volunteries.
>First I segment the images by using NIH3 data as template. Should I
>'Affine regularisation' to averaged template image?
There is no special regularization prepared for children templates. However, the proposed
option or the default MNI regularization might also work.
>
>And I segmented my data by using VBM5 toolbox and I selected 'non-linear
>only' option and as tissue priors 'old SPM approach'. According to my
>readings using these options in preprocessing data correct the total volume
>differencies and there is no need an ANCOVA correction. Is this correct?
Yes, this option was thought to skip the additional use of a correction for TIV. Furtermore,
you can also try the "no priors" option. This experimental option might improve the
segmentation accuracy of children data. See Altaye et al. 2009:
http://dbm.neuro.uni-jena.de/pdf-files/Altaye-NI08.pdf
And
>secondly If I use an ANCOVA correction
>and use total intracranial volume as
>coveriance of no interest may be I do overcorrection and my results will be
>failed. Is this correct or should I use total intracranial volume in
>an ANCOVA model?
I would only use the correction for TIV for the standard modulated data.
Best regards,
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
>
>Sorry for these may be silly questions.
>Thanks for all
>ASLÝ
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