An image can be in MNI space, but have any voxel size. Generally, it
is the mm coordinates that are reported, rather than the voxel
indices. I figured that 1.5 mm seemed like a reasonable default
resolution to work with for Dartel normalised images. As computers
get more powerful and disks cheaper, the default resolution for this
sort of thing is likely to increase.
Best regards,
-John
On 13 October 2011 06:39, David Yang <[log in to unmask]> wrote:
> Dear SPMers:
>
> Since it was a basic question, I could not find any answer from manual or discussions in the forum.
>
> As the SPM MNI space (voxel size 2mmx2mmx2mm and dimension: 91x109x91) and DARTEL-processed images (voxel size: 1.5mmx1.5mmx1.5mm and dimension: 121x145x121) had different voxel size and dimensions, I wondered if it was needed to perform some transfrom from MNI coordiates to DARTEL-procesed images?
>
> I suspected the step of "Normalise to MNI Space" in DARTEL tools had dealt with such problem but why the result image still had image voxel size 1.5mmx1.5mmx1.5mm and dimension: 121x145x121?
>
> Furthermore, for my current work, I have to review literature and chose the hypothesis driven anatomical VOI based the reported MNI coordinates from related papers. I used WFU_Pickatlas and entered the coordinates in the software to get the anatomy labeling based on atlas (eg. AAL). I wondered if the difference voxel size or dimension of SPM MNI space and DARTEL-processed images make such process invalid?
>
> Thanks for help!
>
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