So we're having a problem with the segmentation of the fornix. It is currently creating a cortical surface (i.e. a separation between the main and pial surfaces) despite removing the fornix from the brainmask. We have also tried filling in the white matter mask without any improvement. Do you have any suggestions on how to fix this? We have included a couple of pictures for your reference- the brainmask (with the deleted fornix) with the main and pial surfaces visible, and the corresponding white matter mask. Thanks for your response, True Price Summer Intern- King Lab