[Freesurfer] unit of corpus callosum segmentation

Hi all,

I have a quick question related to the corpus callosum segmentation: I read in previous posts that the reference explaining more about the CC subdivision in 5 segments was the one by Rosas et al, Neuroimage 2010. But in this publication, you show thickness of the corpus callosum as the main outcome variable, with average values ranging from ~4 to 9 mm. And when I extract the values from the aseg.stats, in my dataset I rather get average values that are ranging between ~400 and 900 depending on the segment. Do these values correspond to thickness in mm/100, or to area, or to something else? Is that a thickness measurement, or a surface area measurement?

Many thanks in advance for your reply,

Marie