Hi Freesurfer Team and Doug,

Is there any way to derive the gtmstats from Petsurfer within a longitudinal design? 

Could I get your take on the steps below?

1. Extract GTM stats from each PET time-point (registered to the closest structural MRI in time).

2. Manually compute the percent change per region across time-points.

Alternatively, would it be more ideal to resample the PET data to the surfaces at each time point before extracting the MGX-based ROI PET data with mri_segstats? With this approach, it would be possible to use the longitudinal commands, right?

Thanks!

Elijah