Hello,

I am trying to use PVE correction on preprocessed PET data downloaded from the Alzheimer's Disease Neuroimaging Initiative(ADNI) database.

I have a couple of questions:

1) I am using the co-registered, averaged image of the dynamic images, and it seems from your answers here (https://www.mail-archive.com/freesurfer@nmr.mgh.harvard.edu/msg43435.html)that for static PET images, #3~5 will be different. Could you explain how I would need to enter the command differently?

2) I already have segmentations of my MRI images obtained via FreeSurfer(v.5.2)'s cortical parcellation. Would I still have to do procedure #1 (gtmeseg --s subject) ? I did try using xcerebralseg because it seemed from the help command that in my case where I already have some FS segmentations that I should use this one:

 

You can use your own segmentation or a modified FS segmentation.
It will be easiest if you modify apas+head.mgz to insert your
segmentations. apas+head.mgz is created by gtmseg but you can
create it with

xcerebralseg --s $subject --o $SUBJECTS_DIR/$subject/mri/apas+head.mgz

However when I do try I got the following error:

 

Thanks a lot in advance,

Regards,

Subin