Hi,
This is regarding the older post that I made a little while back
(https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0907&L=SPM&T=0&F=&S=&X=049D2E4628E80D3A88&Y=narayanan.32%40osu.edu&P=239575).
Many thanks to Neil who helped me understand that. I have thought about this
and I have some additional questions. I would've replied earlier except I
kept getting an error when running coreg: estimate and reslice
(https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0908&L=SPM&T=0&F=&S=&X=671DF6512C6C596D9F&Y=narayanan.32%40osu.edu&P=34989).
My understanding from previous posts is, realign basically makes sure that
there is a voxel-to-voxel correspondence between the different volumes of
the EPI image. And coreg makes the EPI images from the realign step in the
same orientation as the T1W anatomical scans.
The second part about coreg does confuses me though. Coreg aligns the EPI
images with the T1 images. But it isn't necessary to make it the same
resolution as the T1W scan. By align, I am thinking overlap. How can you
align them without making them the same resolution? What exactly does Coreg
do to the images?
Secondly, realign, coreg and normalize have options to either 'estimate',
'reslice' or 'estimate&reslice.' I've always been selecting the
'estimate&reslice' option when doing the preprocessing for all three steps.
What does each one of them do? Which one is the best option for each step? I
wanted to test all 3 of them, but I am getting an error using the
'estimate&reslice' option. Any assistance would be greatly appreciated. Thanks.
- Ananth
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