Dear all,
Freesurfer 6 creates pial and white matter surfaces around the optic chiasm in some of my subjects (see the attached pictures). When I check the aparc.DKTatlas+aseg.mgz, sometimes these places are segmented as optic chiasm or nothing (which seems to be good), but sometimes this region is segmented as white matter or medialorbitofrontal cortex. Could somebody please confirm that these surface inacuracies don't matter as long as the area is not segmented as a cortical region or white matter in the aparc.DKTatlas+aseg.mgz file, and I should correct it if missegmented as a cortical region or white matter?
I suspect that I should correct the wm.mgz. However, all of the brainmask, aseg and wm corrections are done on my subjects and I'd like to correct this new error without loosing those corrections. How should I correct this new wm inaccuracy without loosing my earlier aseg corrections?