Hello,
> Aplogies if it sounds stupid
I hope I did not convey that impression! The source of my
misunderstanding your question might equally likely be my stupidity.
> What I had planned initially was to use the calculated TIV as a
> covariate at the template creation stage in TOM.But would require
> estimating the TIV first based on segmentation with priors from some
> template in the first place. Thats where I was confused.
If you used, say, cat12, then the template would not factor into the
segmentation step and you could still validly use the TIV from that
procedure. But I can still not quite understand where you would use that
information in the template creation step, hence...
> As your suggestion,it would be good to add it as a covariate later on in
> the analysis but not at the TOM Template creation stage,if I understand
> right
I think that what you think I think is correct :)
Cheers
Marko
> On Wed, Nov 16, 2016 at 4:58 PM, Marko Wilke
> <[log in to unmask]
> <mailto:[log in to unmask]>> wrote:
>
> Hello,
>
> I also have one more question/problem
>
>
> Only one? ;)
>
> I have used the TOM toolbox and have a children's template.
>
>
> OK.
>
> the template is created from typically developing population and
> one of my
> groups is autistic,I would like to control for the effects of Total
> Intra Cranial Volume
>
>
> OK.
>
> But to estimate TIV I would need a template for segmentation
>
>
> Yes, but why can you not use TOM's tpm for segmentation? That would
> actually be the idea behind it.
>
> and a template with TIV as a covariate would be better
> suited to the population(I assume)-Which is kind of circular.
>
>
> I am not sure I follow you. You want to use an externally generated
> template which is not biased towards either of your groups, which is
> going to be hard if the one group has a disease and the other does
> not. One way out would be to generate your own template from your
> dataset but I mentioned before that you would need a very large
> group for this, the larger the more diverse your population is.
> Another approach would be to take this potential bias into account
> by looking at (for example) TIV between your groups and potentially
> use it as a covariate later-on, which is what I think is what you
> are planning to do. Why you would need the TIV of the template, I
> did not quite get but you could of course calculate each tissue
> class volume in the 6-volume TPM that TOM gives you... was that what
> you were asking?
>
> Kindly comment on the same
>
>
> I did, but I am not sure this helped...?
>
> Cheers
> Marko
>
>
> --
> ____________________________________________________
> Prof. 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]
> <mailto:[log in to unmask]>
>
> http://www.medizin.uni-tuebingen.de/kinder/epn/
> <http://www.medizin.uni-tuebingen.de/kinder/epn/>
> ____________________________________________________
>
>
--
____________________________________________________
Prof. 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/
____________________________________________________
|
