[Freesurfer] aparc+aseg voxels labeled as "unknown"

Hello,

After completing the FreeSurfer Recommended Reconstruction, we have noticed that in aparc+aseg, many subjects exhibit small clusters of voxels in the medial temporal lobe that are labeled as "ctx-lh-unknown" or "ctx-rh-unknown". These clusters are mostly found on the boundaries between the amygdala, hippocampus, inferior lateral ventricles, and cerebral white matter. Please refer to the attached screen shot for an example.

How can we deal with this problem? One possible solution that we thought of was to apply the corresponding label in aseg.mgz for each affected voxel in aparc+aseg.mgz, but we thought we would ask if there is a better way.

Thank you, Nikhil Chandra