Hi Deirdre, To answer your first question, most wm edits only span a couple slices so you might as well edit every slice. However, I have seen wm edits on every other slice work before. If the error you are trying to fix spans many slices then you may be better off trying control points first, which you can definitely place every second/third slice.

Second question, the horn is being excluded in the wm.mgz? Is it still being correctly segmented in the aseg.mgz?

Third question, yes you can by creating a point set. Be sure to select 'Control Points' and not 'Way Points' when creating a new point set. Also, the control points point set should be saved as control.dat in the subjects tmp dir. -Louis

On Mon, 17 Sep 2012, Deirdre O Shea wrote:

Hi all, I'm new to FreeSurfer and so have a few questions that you may be able to anwser.

My first question is ; when I am making white matter edits do I need to edit every single slice where the inaccuracy is or would every second or third slice suffice to prompt FreeSurfer to autocorrect?

Secondly, in many of our FreeSurfer images, the horn of the lateral ventricles in the coronal images are being excluded from the white matter - is there a way to stop this from happening?

Finally, I find that Freeview is a good way to view the images and although I know it is possible to make some edits such as filling in voxels etc., I wanted to know if it was possible to add control points like that in tkmedit?

Thanks, Deirdre