[Freesurfer] strange eTIV values

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Hello Freesurfer experts,

When I exported the Destrieux and Desikian-Killiany volume values from Freesurfer to SPSS I obtained "strange" eTIV values with 16 digits as follows:

101,632,104,008.0000 134,253,072,953.0000 155,967,056,944.0000 142,085,122,028.0000 181,105,664,397.0000 118,051,287,519.0000 896,135,067,103.0000

With how many decimals Freesurfer exports the eTIV values ?, that is, what is the precision of this measure? I do not know how many decimals this measure has.

Another doubt, it is necessary to make some kind of numerical transformation on the eTIV values before including it as a covariate in the statistical analysis (for example, a logarithmic transformation).

Best,