New subject: Does FS guarantee the same results if run several times?

17 Apr 2020


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Dear Freeserfer developers,
I have run recon-all for a bunch of subjects on the same machine for several
times. When I use the "mris_anatomical_stats" to calculate the statistics
(specifically, I am interested in average cortical thickness), I found that
for the same subject I got different results, as shown below:
$ mris_anatomical_stats -b QEN001 lh
.
128449  86239  243375  2.588 0.876     0.123     0.026     1496
133.3  /xxx./subjects/QEN001/surf/lh.white
$
$ mris_anatomical_stats -b QEN001_old lh
.
128449  86241  229554  2.404 0.835     0.123     0.026     1496
133.3 /xxx./subjects/QEN001_old/surf/lh.white
The results shows that some of the stats numbers ( such as the number of
vertices) are the same, but the "average cortical thickness +- standard
deviation (mm)" are different, and they differ quite a lot.
I have tried several subjects; some of them get the all-the-same results,
some of them not.
I am sure the subjects and the corresponding images are the same. Are these
expected results?
Thanks!
Xiaojiang