Hi all,

We were sent a FreeSurfer annotation file that denotes some ROIs we're interested in. What's the proper way to map this annotation to the cortical ribbon volume and get an estimate of that volume for each ROI? I've already registered the annotations to the subject from fsaverage space using mri_surf2surf. I'm thinking something like:

mri_label2vol --annot {registered_annotation_file} --temp {$SUBJECT/mri/orig.mgz} --o {output_volume_segmentation_file} --subject {$SUBJECT} --hemi {lh,rh} --identity --proj frac 0 1 0.01

And then run mri_segstats on the output_volume_segmentation_file

This seems to do what I need, but I want to confirm that I'm not missing import details. I'm also not entirely sure what the 'delta' parameter of the --proj flag is doing. I gather that it's some kind of step size, but will it have a big impact on the resulting ribbon volume?

Thanks for any help!

Best,

John