Brainordinate
      Brainordinate
      is a brain location that is
      specified by either a surface vertex (node) or a volume
      voxel.  Brainordinates include grayordinates (gray-matter
      vertices or voxels) and whiteordinates (white-matter
      voxels).  CIFTI
      files contain a list of selected brainordinates and can handle
      combined surface/volume representations.