The GTM operates on regions, so you can't do trilin interp. The operations that you describe below are not used in mri_gtmpvc. If you are trying to get something close to what the GTM does, then use nearest neighbor
On 2/14/19 3:43 AM, Matthieu Vanhoutte wrote: > External Email - Use Caution > > Hi Douglas, > > Could you help me concerning my previous questions ? > > Thanks, > Matthieu > >> Le 11 févr. 2019 à 17:37, Matthieu VANHOUTTE <matthieuvanhou...@gmail.com> a >> écrit : >> >> Hi Douglas, >> >> Thanks for clarification. Why use "nearest neighbor" instead of classical >> "trilinear" interpolation ? >> >> Should it be done as well when projecting from volume to surface with >> mri_vol2surf ? >> >> Best, >> >> Matthieu >> >> On 11/02/2019 17:32, Greve, Douglas N.,Ph.D. wrote: >>> It will not used trilinear interp. Try it with nearest neighbor >>> >>> On 2/10/19 11:55 AM, Matthieu Vanhoutte wrote: >>>> External Email - Use Caution >>>> >>>> Dear Douglas, >>>> >>>> Before using "mri_gtmpvc --psf 0 --no-tfe -- rbv" according your advice to >>>> obtain voxel-wise output rescaled without PVC correction, I have done >>>> sequentially the different steps to obtain this output. However, when >>>> comparing voxel-wise rescaled output (rbv.nii.gz) between the two methods, >>>> final values at each voxel are not the same… >>>> >>>> To obtain first rescaled voxel-wise output I have used sequentially these >>>> steps: >>>> 1. Concatenate transforms from PET space to gtmseg.mgz >>>> 2. Register native PET into gtmseg space (trilin. interpolation) >>>> 3. Compute mean PET inside reference regions (with regions masks from >>>> gtmseg.mgz) >>>> 4. Compute intensity normalized PET images in gtmseg space >>>> >>>> Doesn’t the "mri_gtmpvc --psf 0 --no-tfe -- rdv" command use these same >>>> steps ? >>>> >>>> Best, >>>> Matthieu >>>> >>>> _______________________________________________ >>>> Freesurfer mailing list >>>> Freesurfer@nmr.mgh.harvard.edu >>>> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >>> _______________________________________________ >>> Freesurfer mailing list >>> Freesurfer@nmr.mgh.harvard.edu >>> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
