John,
just following up on the last part of your question:
> Another question we have is regarding templates. I know that the VBM8
> Toolbox does not use priors in its segmentation per se but only for the
> spatial normalization per the manual. I know for pediatric cases it is
> good to create your own template, but what are users opinions on using
> the Template-O-Matic to generate templates for older individuals for
> aging studies? We have an aging study I am exploring implementing this
> pipeline for as well. One thing we were considering is to generate a
> template using the ADNI cohort and use that for our data. Does this
> seem reasonable or is it overkill (we should just use the default VBM8
> processing without a customized template)? If it is reasonable would
> you use the entire cohort to generate the template or just healthy
> controls?
I believe that the further away your population is from the population
that contributed to the priors, the more important it is to be aware of
this as being a confound. So yes, I would recommend using a custom
template when investigating aging. I think that, if you have a
reasonably large population, you could use that to create your own TOM
regression parameters, but using an independent large cohort would
probably be a good alternative (and you could use it for other studies,
too ;) Regarding whom to include, you should always include everybody in
your cohort lest processing be biased by only using the controls (or use
a totally independent cohort).
Cheers,
Marko
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PD Dr. med. Marko Wilke
Facharzt für Kinder- und Jugendmedizin
Leiter, Experimentelle Pädiatrische Neurobildgebung
Universitäts-Kinderklinik
Abt. III (Neuropädiatrie)
Marko Wilke, MD, PhD
Pediatrician
Head, Experimental Pediatric Neuroimaging
University Children's Hospital
Dept. III (Pediatric Neurology)
Hoppe-Seyler-Str. 1
D - 72076 Tübingen, Germany
Tel. +49 7071 29-83416
Fax +49 7071 29-5473
[log in to unmask]
http://www.medizin.uni-tuebingen.de/kinder/epn/
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