Wired head mask after importing subject anatomy

Dear Francois and BST users,

I'd like to ask a question about the head mask. After importing the subject's anatomy (freesurfer folder), I obtained an extremely wired head mask shown as follows:
without_cortex with_cortex

I assume the 'rhinoceros horn' on the nose may be due to the small mirror in front of the face during MRI collecting. However, I have no idea about the 'spikes' on the scalp and what may cause it?
Is this head mask ok for further source estimation analysis? It seems that I can do nothing since all things are automatically imported from the freesurfer folder.
Looking forward to your kind reply and thanks in advance.

Best Regards,

The head surface is not imported from FreeSurfer, it is reconstructed by Brainstorm. You can try different parameters to reduce the impact of the artifacts in the MRI (electrodes?):

Do your best with the head surface reconstruction, and go on with the source estimation, it should not alter the results too much. If you are using a BEM model, the local irregularities might cause some numerical instabilities. Look at the source maps carefully, check for abnormal values, compare with spherical models to make sure you are on the right tracks.

Dear Francois,

Sorry for my late reply and thanks so much. I will have a try to eliminate the artifact and will keep posting if any further problem.

Best Regards,