If the AC is within about 2 or 3 cm of 0,0,0 and the orientation is
within about 10 - 15 degrees of axial, then re-orientation may not be
necessary. This does of course depend on the field of view and
quality of your images. With a smaller field of view, the starting
estimates for any image registration may need to be closer than they
would otherwise need to be.
Reorienting/repositioning may be done with the Display button. First
of all, figure out what combination of rotations (in radians) and
translations (in mm) will position one of your images appropriately.
Once you are happy with this, click the "Reorient Images..." button,
and select those images that you want to reorient in the same way.
Best regards,
-John
On 14 February 2012 14:30, Kailyn Bradley <[log in to unmask]> wrote:
> Hello all,
>
> I have what I imagine is a fairly simple and novice question about data
> acquisition/preprocessing that I'm afraid I don't know the answer to...I
> acquired functional images parallel to the ACPC line. Before preprocessing,
> should I reorient the images to the ACPC axis so that the anterior
> commissure is is in the 0 0 0 coordinate position for all of my subjects?
> Does SPM have a way to do this? Is this a mandatory step, or does SPM have
> some way of dealing with the fact that everyone's ACPC line is at a slightly
> different angle during preprocessing or further analysis? Any information of
> this topic would be of great help to me. Thank you.
>
> -Kailyn
>
>
>
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