[Freesurfer] adding grey matter

Hi Freesurfers, I have a question about pial editing. I have some reconructions in which there's a lot of grey matter excluded, and consequently white metter too. I did correct these images manually by control points editing, and then autorecon2-cp autorecon3, but some cortical grey matter continues to not be included in the pial surface, and I have white matter areas that are still not included in either the pial or white matter boundaries. Is there anyother ethods for adding grey matter in the pial surfeces other than editing control points (such as by editing voxels to add grey matter), or something like that? Thanks for your help. Claudia