RAS to MNI Coordinate Conversion in fMRIPrep Output

Hi @oesteban ,

I am trying to get MNI coordinates back into native T1w space but the calculated coordinates with antsApplyTransformsTo Points does not give the result I expect. I did check if the transform works well to transform the T1w image into MNI space and that is the case.

Here is what I did:

  • Choice of parameters in MNI space with FSLeyes, at the genu of the Corpus Calosum:

  • Creation of the CSV file with those coordinates:
    echo -e "x,y,z,t,label,comment\n2,34,3,0,0,0" > test.csv
  • antsApplyTransformsTo Points command:
    antsApplyTransformsToPoints -d 3 -i test.csv -o test_native.csv -t sub-03_ses-01_from-T1w_to-MNI152NLin2009cAsym_mode-image_xfm.h5
    => resulting coordinates:
$ cat test_native.csv 
x,y,z,t,label,comment
2.07629,5.26715,-1.39167,0,0,0

View of those coordinates on the native image in FSLeyes:

Any idea of what went wrong?
As I said the H5 transform performs well well applied to the native image with antsApplyTransforms