warping MNI space ROIs to match TT_icbm452+tlrc


I have a whole slew of binary ROIs in MNI152 space @ 1mm resolution (182x218x182 voxels). Is there straightforward AFNI incantation to warp these from MNI152 space to match TT_icbm452+tlrc @ 4mm isotropic?

Usually I do this the other way around (TT->MNI) and use fsl to do the job. Now needing to go the opposite way I’ve realized I’ve no idea how to do this in AFNI :frowning:

Any help much appreciated.


There are a few ways to transform to Talairach space from MNI space.

for N27 in MNI (MNI_N27) space data, this works best

adwarp -prefix tt_testmni_region -resam NN -apar TT_N27+tlrc -dpar testmni_regions+tlrc. -force

Use the two-part Brett transform for the ICBM452 or MNI-152 datasets, this probably works better

3dWarp -mni2tta -NN -prefix tt_testmni_region_brett+tlrc testmni_regions+tlrc.

color in AFNI with separate colors per region

3drefit -cmap INT_CMAP testmni_regions+tlrc.
3drefit -cmap INT_CMAP tt_testmni_region*+tlrc*.HEAD

You could also use the Lancaster transformations too. See this previous post for some gory details. Check your results in the afni GUI.


Thanks Daniel. I had completely forgotten about the 3dWarp option.