> 1- i must cut the babys' head at first to separate it from their body, the
> first question arise there: from where we must cut the head, and why we
> must cut it like the other tempates of the heads?
I hope you are talking about the images - rather than the babies themselves.
If so, then I would suggest obtaining a field of view that is slightly larger
than the field of view of the template images supplied with SPM.
> 2- who we can make template? at first we must chose some good heads, and
> then coregister and normalize them, is ther any paper or sites that can
> help me on this subjects? for example describe the procesdor to make
> template?
Generally, it involves spatially normalising a number of brain images, and
averaging them. You would create the spatially normalised images using the
"Template" bounding box. You would need to change the spatial normalisation
defaults to do this.
Many average brains (e.g. those created by the MNI) are created using affine
registration only, so it may be a good idea to do the same. Again, this is
something that you would specify via the Defaults button.
Once you have a number of spatially normalised images, then simply create an
average of them, and smooth by 8mm. This can then be used as a template for
spatial normalisation in SPM2.
If you want datasets for doing VBM, then you will also need to create tissue
probability maps for grey matter, white matter and CSF. There are tools
avaliable at http://dbm.neuro.uni-jena.de/vbm.html which may help for this.
> 3- what is differences between realignment and co-registration?
Realignment is intended to realign fMRI or PET images of the same subject.
Coregistration is intended to register images of the same subject together,
but they can be of the same or different modalities.
Best regards,
-John
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