Hi,
I am using FS v5.3 and I had two questions regarding the calculation of cortical thickness in the stats files:
1) Is the average cortical thickness of each structure (i.e. precuneus) calculated by averaging the cortical thickness values of each location in that structure?
2) Is the mean thickness calculated in the *h.aparc.stats (or in the other aparc stats files) calculated by averaging the cortical thickness values of all the structures in that hemisphere, or by using a weighted average of the cortical thicknesses of the structures included in that hemisphere?
Thanks, Panos
On 11/12/2013 11:26 AM, pfotiad@nmr.mgh.harvard.edu wrote:
Hi,
I am using FS v5.3 and I had two questions regarding the calculation of cortical thickness in the stats files:
- Is the average cortical thickness of each structure (i.e. precuneus)
calculated by averaging the cortical thickness values of each location in that structure?
Yes
- Is the mean thickness calculated in the *h.aparc.stats (or in the other
aparc stats files) calculated by averaging the cortical thickness values of all the structures in that hemisphere, or by using a weighted average of the cortical thicknesses of the structures included in that hemisphere?
It is the mean over all vertices without regard to structure doug
Thanks, Panos _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
Hi Doug,
Thanks for your response. In addition, as it it mentioned in the wiki page the total white matter volume is volume inside the white surface minus anything that is not WM. Would it be correct to say that even though the total white matter volume calculation is based on a surface-based volume calculation, the calculation of the volume of any structure enclosed that is not WM, is computed based on a volume-based volume calculation?
Thanks, Panos
On 11/12/2013 11:26 AM, pfotiad@nmr.mgh.harvard.edu wrote:
Hi,
I am using FS v5.3 and I had two questions regarding the calculation of cortical thickness in the stats files:
- Is the average cortical thickness of each structure (i.e. precuneus)
calculated by averaging the cortical thickness values of each location in that structure?
Yes
- Is the mean thickness calculated in the *h.aparc.stats (or in the
other aparc stats files) calculated by averaging the cortical thickness values of all the structures in that hemisphere, or by using a weighted average of the cortical thicknesses of the structures included in that hemisphere?
It is the mean over all vertices without regard to structure doug
Thanks, Panos _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
-- Douglas N. Greve, Ph.D. MGH-NMR Center greve@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422
Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 www.nmr.mgh.harvard.edu/facility/filedrop/index.html Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
yes
On 11/12/2013 03:21 PM, pfotiad@nmr.mgh.harvard.edu wrote:
Hi Doug,
Thanks for your response. In addition, as it it mentioned in the wiki page the total white matter volume is volume inside the white surface minus anything that is not WM. Would it be correct to say that even though the total white matter volume calculation is based on a surface-based volume calculation, the calculation of the volume of any structure enclosed that is not WM, is computed based on a volume-based volume calculation?
Thanks, Panos
On 11/12/2013 11:26 AM, pfotiad@nmr.mgh.harvard.edu wrote:
Hi,
I am using FS v5.3 and I had two questions regarding the calculation of cortical thickness in the stats files:
- Is the average cortical thickness of each structure (i.e. precuneus)
calculated by averaging the cortical thickness values of each location in that structure?
Yes
- Is the mean thickness calculated in the *h.aparc.stats (or in the
other aparc stats files) calculated by averaging the cortical thickness values of all the structures in that hemisphere, or by using a weighted average of the cortical thicknesses of the structures included in that hemisphere?
It is the mean over all vertices without regard to structure doug
Thanks, Panos _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
-- Douglas N. Greve, Ph.D. MGH-NMR Center greve@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422
Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 www.nmr.mgh.harvard.edu/facility/filedrop/index.html Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/
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
Great, thanks Doug!
Panos
yes
On 11/12/2013 03:21 PM, pfotiad@nmr.mgh.harvard.edu wrote:
Hi Doug,
Thanks for your response. In addition, as it it mentioned in the wiki page the total white matter volume is volume inside the white surface minus anything that is not WM. Would it be correct to say that even though the total white matter volume calculation is based on a surface-based volume calculation, the calculation of the volume of any structure enclosed that is not WM, is computed based on a volume-based volume calculation?
Thanks, Panos
On 11/12/2013 11:26 AM, pfotiad@nmr.mgh.harvard.edu wrote:
Hi,
I am using FS v5.3 and I had two questions regarding the calculation of cortical thickness in the stats files:
- Is the average cortical thickness of each structure (i.e.
precuneus) calculated by averaging the cortical thickness values of each location in that structure?
Yes
- Is the mean thickness calculated in the *h.aparc.stats (or in the
other aparc stats files) calculated by averaging the cortical thickness values of all the structures in that hemisphere, or by using a weighted average of the cortical thicknesses of the structures included in that hemisphere?
It is the mean over all vertices without regard to structure doug
Thanks, Panos _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
-- Douglas N. Greve, Ph.D. MGH-NMR Center greve@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422
Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 www.nmr.mgh.harvard.edu/facility/filedrop/index.html Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/
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
-- Douglas N. Greve, Ph.D. MGH-NMR Center greve@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422
Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 www.nmr.mgh.harvard.edu/facility/filedrop/index.html Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
freesurfer@nmr.mgh.harvard.edu
-
Douglas N Greve -
pfotiad＠nmr.mgh.harvard.edu