Dear Daniel,
Recently I encountered a problem in MNI and Talairach coordinate conversion. I want to use some MNI coordinate from some meta-analysis, but if I input the MNI coordinate in AFNI GUI window "Jump to (MNI)", and input "0 0 0", and switch to "Where Am I?"
it shows that
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Orignial input data coordinates in TT_N27 space
Focus point (LPI) =
-0 mm [L], -3 mm [P], 4 mm [S] {TLRC}
-0 mm [L], -0 mm [P], -0 mm
{MNI} NeuroSynth SumsDB
-0 mm [L], -4 mm [P], 5 mm [S] {MNI_ANAT}
////////////////////////////////
But if I use command version whereami
$ whereami 0 0 0 -lpi
it gives
///////////////////////////////
Orignial input data coordinates in TLRC space
Focus point (LPI) =
0 mm [L], 0 mm [P], 0 mm [S] {TLRC}
0 mm [L], 0 mm [P], 0 mm [S] {MNI} <a href=...../a>
-0 mm [L], -4 mm [P], 5 mm [S] {MNI_ANAT}
/////////////////////////////
It is not the same, I see that the transform is both Brett transform.
I also use GingerALE's "Convert Foci" tool, it report Talairch coordinate in several flavours of MNI coordinate
(0,0,0) in TLRC, will be (0,0,0) in Brett MNI, (1.12, .87, -3.6) in FSL MNI, (1.04, 1.46, -4.75) in SPM MNI, and (1.08, 1.17, -4.18) in other MNI
(0,0,0) in MNI, will be (0,0,0) in Brett TLRC, (-1.07, -1.02,3.19) in FSL MNI->TLRC, (-1.02, -1.77, 4.09) in SPM MNI->TLRC, and
(-1.04, -1.39, 3.65) in other MNI->TRLC
So I am messed up by these transform, when input MNI coordinate into AFNI, some structure may display to out of brain tissue.
Thank you very much!
Best,
FC