Dear Josse and all: Before posing the parcellation problem with respect to patients with cortical lesions, I was wondering to ask if anybody has a clue on how the segmentation of the cortex/WM might work in patients with juxtacortical/cortical lesions.
In other words: how the drop of the signal given by cortical lesions affects the segmentation of the cortex? Also, how much partial (CSF) volume voxels due to the empty space left by cortical lesions may affect the cortical thickness measurements?
Thanks, -francesca
Francesca Bagnato, MD NIB-NINDS-NIH 10 Center Drive Building 10, Room 5B16 Bethesda, MD, 20892 USA ph #: 001-301-402.6391 fax #: 001-301-402.0373
-----Original Message----- From: Goulven Josse [mailto:goulven@uchicago.edu] Sent: Friday, October 21, 2005 6:29 PM To: freesurfer@nmr.mgh.harvard.edu Subject: [Freesurfer] Anatomical parcellation in patients
Dear freesurfers,
We are trying to analyse data from patients who had an early stroke. I did one automated parcellation (Fischl et al, 2004) in a patient with a peri-ventricular enlargement associated with a large overall atrophy of the injured hemisphere. I was pleased to find out that, even in the injured hemisphere, the anatomy was -apparently- well parcellated. I am now thinking of applying the parcellation to other subjects with a similar lesion and, possibly, to subjects with a much bigger, cortical, lesion.
Before going ahead, I am wondering if anyone had an opinion about whether it makes sense to use this parcellation in patients, while it was (i think) originally designed for normal brains. Variability is huge in normals but still ...
thanks ! Goulven Josse (Brain Research Imaging Center, U of Chicago)
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Hi Francesca,
this is tough to answer as it depends on the exact location of the cortical lesion, and the thickness of the underlying white matter. As you know, we have done a fair number of MS subjects, so in general it's okay, but I can certainly imagine scenarios in which things fail.
sorry I can't be more help. Bruce
On Fri, 21 Oct 2005, Bagnato, Francesca (NIH/NINDS) wrote:
Dear Josse and all: Before posing the parcellation problem with respect to patients with cortical lesions, I was wondering to ask if anybody has a clue on how the segmentation of the cortex/WM might work in patients with juxtacortical/cortical lesions.
In other words: how the drop of the signal given by cortical lesions affects the segmentation of the cortex? Also, how much partial (CSF) volume voxels due to the empty space left by cortical lesions may affect the cortical thickness measurements?
Thanks, -francesca
Francesca Bagnato, MD NIB-NINDS-NIH 10 Center Drive Building 10, Room 5B16 Bethesda, MD, 20892 USA ph #: 001-301-402.6391 fax #: 001-301-402.0373
-----Original Message----- From: Goulven Josse [mailto:goulven@uchicago.edu] Sent: Friday, October 21, 2005 6:29 PM To: freesurfer@nmr.mgh.harvard.edu Subject: [Freesurfer] Anatomical parcellation in patients
Dear freesurfers,
We are trying to analyse data from patients who had an early stroke. I did one automated parcellation (Fischl et al, 2004) in a patient with a peri-ventricular enlargement associated with a large overall atrophy of the injured hemisphere. I was pleased to find out that, even in the injured hemisphere, the anatomy was -apparently- well parcellated. I am now thinking of applying the parcellation to other subjects with a similar lesion and, possibly, to subjects with a much bigger, cortical, lesion.
Before going ahead, I am wondering if anyone had an opinion about whether it makes sense to use this parcellation in patients, while it was (i think) originally designed for normal brains. Variability is huge in normals but still ...
thanks ! Goulven Josse (Brain Research Imaging Center, U of Chicago)
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@nmr.mgh.harvard.edu
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Bagnato, Francesca (NIH/NINDS) -
Bruce Fischl