.STATS File Extension
File TypeFreeSurfer Statistics File
What is an STATS file?
Data file generated by FreeSurfer, a program used for generating brain images from MRI data; contains output data such as subcortical segmentation data (i.e., aseg.stats), cortical parcellation data (i.e., aparc.stats), and other information that can be used for generating an output image.
STATS files are saved in a plain text format, but you should refer to the FreeSurfer documentation to understand the particular format of the file.