Assuming these are cortical lesions, you can use mri_vol2surf to map them as overlays onto the surface. Use the --regheader flag since they are already in the conformed space. You can even specify the target subject to be fsaverage to have the overlay be on the fsaverage surface (if not, then use mris_apply_reg to map to fsaverage). Once you have all subjects' data in fsaverage space, then you can run mri_concat overlay1.mgz overlay2.mgz ... overlayN.mgz --o stack.mgz to put them all into the same file. You can then run stats on them with mri_glmfit (make sure to use the --no-prune option) or you can compute the mean with mri_concat stack.mgz --mean --o stack.mean.mgz

On 9/9/2020 10:51 PM, Horn, Mitchell Jacob wrote:

Dear FS Experts,

I would like to show the distribution and overlap of lesions on an average inflated brain surface as a heat map.

I have a 150 subjects of which I’ve made masks of T2 lesions and moved into their respective subject-T1w-spaces (using T1.mgz as reference) where I have completed recons.

What are the steps in bringing these subject-T1w-space lesions into an average brain and presenting them as a surface? Again, I hope to show the lesion distribution scaled by the number of times (out of 50 subjects) that any voxel is a lesion.

Thanks in advance,

Mitch

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