Dear Wei,
I use to normalize, but I guess that the need of specifying the origin
is in order to:
- have the brain volumes in "correct" axial orientation "near" to the
glass brain
- therefore you are able of creating a bounding box for the volumes (so
you can take out of the statistics any unimportant (i.e. out of brain) data.
You can test that the brain scan is near the AC/PC by means of the
Check.Reg button.
Best regards,
Juan J.
pengxu wei wrote:
> Dear list,
>
> The manual recommend 'specify where you think the anterior commissure is
> with the ORIGIN in the header of the first scan' if skiping normalisation when preprocessing data.
>
> Would anyone like to tell me why we need such a step. Even the AC is set to a correct point, the PC may lie somewhere unsuitable. So what is the meaning of it? Besides, in functional images it is often not easy to recognise where AC is.
>
> Regards,
>
> wei
>
>
> ---------------------------------
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