Hi all,
Can anyone tell me how freesurfer defines Intracranial volume, Brain segmentation volume and Brain mask volume? What is the difference between the 3 measures?
-Dhruman
the Intracranial volume we estimate using the method proposed by Denise Head and Randy Buckner - look at the det of the talairach xform and use it to infer ICV (what they call eTIV).
Brain segmentation volume: volume of all brain voxels in the aseg Brain mask volume: volume of all voxels after skull stripping.
The latter will include sulcal csf, which the fomer won't. The eTIV stuff is pretty new and we've only done a bit of validation on it (Brad Dickerson manually labeled one T2 dataset and the eTIVs were in pretty good agreement with the manual measurement), so I would use it with a bit of caution.
cheers, Bruce
On Fri, 30 Jun 2006, Goradia, Dhruman D wrote:
Hi all,
Can anyone tell me how freesurfer defines Intracranial volume, Brain segmentation volume and Brain mask volume? What is the difference between the 3 measures?
-Dhruman
Dhruman,
At the top of this page is a link to the ICV estimation paper:
http://surfer.nmr.mgh.harvard.edu/fswiki/eTIV
Nick
On Fri, 2006-06-30 at 12:45 -0400, Bruce Fischl wrote:
the Intracranial volume we estimate using the method proposed by Denise Head and Randy Buckner - look at the det of the talairach xform and use it to infer ICV (what they call eTIV).
Brain segmentation volume: volume of all brain voxels in the aseg Brain mask volume: volume of all voxels after skull stripping.
The latter will include sulcal csf, which the fomer won't. The eTIV stuff is pretty new and we've only done a bit of validation on it (Brad Dickerson manually labeled one T2 dataset and the eTIVs were in pretty good agreement with the manual measurement), so I would use it with a bit of caution.
cheers, Bruce
On Fri, 30 Jun 2006, Goradia, Dhruman D wrote:
Hi all,
Can anyone tell me how freesurfer defines Intracranial volume, Brain segmentation volume and Brain mask volume? What is the difference between the 3 measures?
-Dhruman
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
freesurfer@nmr.mgh.harvard.edu
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Bruce Fischl -
Goradia, Dhruman D -
Nick Schmansky