Hi Kun-Han,
this question has been discussed several times. Background is, you
either want an externally-generated template that favors no party
(patients or controls) or, if you have enough subjects yourself (say,
>>100), you should use both patients and controls in order to avoid
preferential processing of one group (say, controls). If you have only
patients in your sample and enough of them, go ahead with creating a
template from them only. Having said that, in newer versions of SPM,
customized templates are not really that much of an issue anymore except
in very special populations (say, children or elderly adults).
Hope this helps,
Marko
John Lue wrote:
> Dear SPMers,
>
> As I know, spatial normalization algorithm minimizes the residual squared difference between the images being normalized
> and the template. In SPM package and most papers, the customized template was created from normal subjects.
> Therefore, my question is:
>
> Why should template be created from normal subjects rather than patients ?
>
>
> Please forgive my ignorance.
>
> Best wishes and thanks,
>
> Kun-Han Lue
>
--
____________________________________________________
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
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http://www.medizin.uni-tuebingen.de/kinder/epn
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