Thank you John and Gabor,
I was using exactly ArtRepair before asking this question. I am not a
stats guy but I would guess a combination of slice alignment based on
information from volume alignment would be a good idea. Say for
example the normal realignment detects a 2-3mm abrupt move. At that
point the best is to adjust slice positions for that volume as well.
ArtRepair does interpolate "bad" slices from the same slice taken
before and after in time. Thus, it inserts a new slice in the volume
that has nothing to do with the rest of the volume. It only works good
for single slice artifacts. For motion problems, it may be more
elegant to realign the slice.
Thank you.
Dorian
2012/9/12 Gabor Oederland <[log in to unmask]>:
> Hello Dorian,
>
>
> Indeed, the whole volume is realigned. The idea is to correct for (rather) slow motion occuring across the whole scanning session. In case only a few slices are affected by motion (e.g. the last few slices acquired), this will inevitably lead to imperfect correction. This should be a minor problem though, except you have abrupt motion onset or heavy motion inside a TR. But then your data probably suffers of signal increases/decreases as well, not only of motion as such.
>
> You might want to try out the SPM toolbox Artrepair http://cibsr.stanford.edu/tools/human-brain-project/artrepair-software.html which allows to detect and correct "bad" slices inside a volume.
>
>
> Best,
>
> Helmut
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