Defining ROI in middle frontal gyrus

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1

Hello,

We need to define an ROI in middle frontal gyrus and extract the x,y,z coordinates for that maximum activation in that ROI. Any advice on how to do this would be appreciated.

Thank you,
Tom

2

Both the Talairach daemon and the Eickhoff-Zilles macrolabel atlases contain that region. I would opt for the E-Z (Eickhoff-Zilles) option here with a version in the same you want to work - MNI, MNI_ANAT or TLRC space, with atlas names and datasets something like CA_ML_N27 (TLRC space), CA_ML_18_MNIA (MNI_ANAT space), CA_ML_18_MNI (MNI space, separately downloadable). For processing data in native ORIG space, you can move the atlas region data with 3dfractionize, 3dWarp or 3dAllineate for affine transformations. Nonlinear transformations can be applied with 3dNwarpApply.

3

Thank you for the advice. Is it possible to obtain explicit instructions on how to take the thresholded Coef map from the stats_REML overlay and use the E-Z atlas mask you recommend to export the significant voxels that are within the middle frontal gyrus? I believe the steps I need are as follows, but I am not sure what the commands would look like:

  1. Export the thresholded coef map from stats_REML
  2. create a middle frontal gyrus mask in native anatomy space (the subject’s MPRAGE scan)
  3. apply the mask to that exported in step 1.
4

I think you probably want to do something like example 9 from 3dcalc’s help.