Hello I would need to use a brain region from the DD_Desai_MPM atlas .
It’s indicated on the website that is uses the TT_N27 template space
but I’m wondering what the difference between the TT_N27 and the TT_152_2009c
cause the 2009c looks way better for resolution and I would like to use that instead.
Any link I can find about that?
We don’t use the Talairached version of the MNI 2009c dataset, but we do have the MNI 2009c in MNI space. The Desai atlases provide a maximum probability map of Freesurfer parcellations from a group of 75 subjects, affinely aligned to the N27 template. There are a few options:
- Move the Desai TT_N27 atlas to MNI space. While the transformation from the TT_N27 space to MNI_N27 is exact by a 12-piece affine transformation, the transformation to MNI 2009c and other MNI variants is not. One could use an approximation like the two-piece Brett transform or a simple precomputed affine transformation, but a nonlinear transformation will be much more accurate.
- Move the 2009c template to the Talairach space. That can be done by manually Talairaching the dataset with the stereotaxic procedure. That’s still available inside AFNI in a hidden menu by right-clicking on the DataDir button. You can also just apply the same 12-piece transformation from the TT_N27 dataset to the MNI_2009c template. That won’t be quite the same thing, but it will be close.
- Use the FreeSurfer parcellation of the MNI_2009c template. This is not from a particular subject or from a set of subjects, but it does give a general parcellation with similar regions as the Desai atlas.
- Use another atlas with the MNI 2009c template. The HCP Glasser and Brainnetome atlases are provided with AFNI.
- Continue with the Desai atlases on the TT_N27 template. These are fine with the same resolution as the MNI 2009c 1mm3 templates, and the Talairached size is closer to most human brain subjects.