Hi everyone!

First time posting. I have what feels like a fairly basic question but I can't find simple answers to.

I have fMRI data in MNI space (which I like because I prefer MNI to Talaraich). However the only way I know how to make Regions of Interest /masks from an atlas was to use the TT_Daemon atlas already in afni.
My goal is to either a) learn how to transform masks from TT to MNI or b) Find another atlas in MNI space already for me to get my masks from.
Although I have used afni so far I am open to non-afni solutions.

For a) my thought was to find a TT template and MNI template brain and transform TT to MNI to get a transformation matrix. I found "MNI_avg152T1+tlrc.BRIK" and "TT_N27+tlrc.BRIK" in /opt/afni/. I used @auto_tlrc -base MNI_avg152T1+tlrc.BRIK.gz -input TT_N27+tlrc.BRIK.gz -suffix .trans to attempt this. I am not sure if it worked but I don't see a transformation matrix or at least I am not sure how to tell what a transformation matrix looks like.
Also, once I do get a transformation matrix, how am I to use that to transform my ROIs to get the same transformation?

For b), I have looked online but haven't found anything. Anyone have tips on how to find this?

I know I am a bit of a novice so please let me know if you need more info to answer my question. Thanks so much for any help you can offer.

Best,
Kirk