PowerPoint Presentation

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Transforming Datasets to Talairach-Tournoux Coordinates

•The original purpose of AFNI was to perform the transformation of datasets to Talairach-Tournoux (stereotaxic) coordinates

•The transformation is user-controlled, not automatic (yet)

•You must mark various anatomical locations, defined in

Jean Talairach and Pierre Tournoux

“Co-Planar Stereotaxic Atlas of the Human Brain”

Thieme Medical Publishers, New York, 1988

•Marking is best done on a high-resolution T1-weighted structural MRI volume

•The transformation defined by the manually placed markers then carries over to all other datasets in the same directory

≤This is where the importance of getting the relative spatial placement of datasets done correctly in to3d really matters

≤You can then write functional datasets to disk in Talairach coordinates

ÂPurpose: voxel-wise comparison with other subjects

ÂMay want to blur functional maps a little before comparisons, to allow for residual anatomic variability: AFNI program 3dmerge