FreeSurfer experts,

I have a question about one of my scans after running recon-all -all. When I open the image with freeview for inspecting brain mask volume.

To give you a better idea of the problem I have attached a screenshot of the T1 volume. All my other images did not show the coloured black background that observed here, so I am wondering what might be the problem.

To open T1 I have used the suggested command:

freeview -v  pial_edits_before/mri/T1.mgz  \
pial_edits_before/mri/brainmask.mgz  \
-f pial_edits_before/surf/lh.white:edgecolor=yellow \
pial_edits_before/surf/lh.pial:edgecolor=red \
pial_edits_before/surf/rh.white:edgecolor=yellow \
pial_edits_before/surf/rh.pial:edgecolor=red

My scans have been processed in nifti format. Also I have previously run nu_correct for correction of artefacts in the top of the brain.

I also opened this particular scan and it looks very similar to the others.

Thank you in advance for your attention.

Pablo