Cortical Hubs

The 'Cortical Hubs' (CHubs) are regions-of-interest defined by cortical thickness differences between older controls and individuals classified as having AD, created using the OASIS data set. These ROIs were used in the study The Dynamics of Cortical and Hippocampal Atrophy in Alzheimer Disease, Sabuncu et al.. See also: Supplemental, and below is a snapshot of a figure from the paper.

Freesurfer v5.2 (and v5.1 local) contains these ROIs as labels, found in the directory $FREESURFER_HOME/subjects/fsaverage/label. There are eight:

These labels are also combined into .annot files: ?h.oasis.chubs.annot

To view these on the fsaverage rh surface:

tksurfer fsaverage rh inflated -annotation oasis.chubs

To map these labels to your subject set (which you would define in a SUBJECTS csh shell var), first you will need to symlink the fsaverage subject into your own subjects dir:

cd $SUBJECTS_DIR
ln -s $FREESURFER_HOME/subjects/fsaverage

Confirm that you see 16 .label files and two .annot files:

ls $SUBJECTS_DIR/fsaverage/label/*chubs*

Now you can do the mapping:

foreach s ($SUBJECTS)
    echo $s
    foreach h (lh rh)
        foreach l (oasis.chubs.ifc \
  .oasis.chubs.ipc \
  .oasis.chubs.ips \
  .oasis.chubs.lateraltemporal \
  .oasis.chubs.mtl \
  .oasis.chubs.retrosplenial \
  .oasis.chubs.tp)
            set cmd=(mri_label2label \
                --srclabel fsaverage/label/${h}${l} \
                --srcsubject fsaverage \
                --trgsubject $s \
                --trglabel $s/label/${h}${l} \
                --regmethod surface \
                --hemi $h)
            echo $cmd
            $cmd
        end
    end
end

Snaphot from the Sabuncu paper:

Notes:

• While the paper says these are from the OASIS data set, they are actually from an earlier data set created at Washington University whose subjects were later included in the OASIS data set. The data set used to create these CHubs is found in the NMR Center here:

/autofs/cluster/con_008/users/washu

• The CHubs ROIs were mapped to the ADNI data set. The ADNI data set is found here:

/autofs/cluster/con_009/users/ADNI

These are a bunch of scripts (in the /scripts dir) which performed those mappings... see *chubs* files.