Dear all,
I am comparing a group of patients with controls. I extracted: cortical volume, surface area, cortical thickness and gyrification index for each subject's lobe. Comparisons between this variables with Total Intracranial Volume as a covariate indicated a difference in frontal and temporal lobes lGI. However, differences were not significant for any of the other variables.
I can´t understand these results from a biological perspective. I was expecting that if a difference exist in lGI it would also manifest in surface area or volume.
Can someone help me with an explanation for this?
Thank you.
ines
Hi,
I am comparing a group of patients with controls. I extracted:
cortical volume, surface area, cortical thickness and gyrification index for each subject's lobe. Comparisons between this variables with Total Intracranial Volume as a covariate indicated a difference in frontal and temporal lobes lGI.
what happens if you do not adjust for intracranial volume? if your patients have abnormal sized lobes then this may be obscured by controlling for head size.
However, differences were not significant for any of the other variables.
I can´t understand these results from a biological perspective. I was expecting that if a difference exist in lGI it would also manifest in surface area or volume.
this paper: http://www.ncbi.nlm.nih.gov/pubmed/18267953
tells us that it is possible for smaller sized brains to have higher folding compared to bigger sized brains. however, it also states that it's much more probable for bigger sized brains to have a higher degree of folding, indeed a strong relationship is shown between brain volume, cortical surface and folding (Figs. 3 and 4c) over large parts of the cortex.
hth, -joost
Can someone help me with an explanation for this?
Thank you.
ines
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.
Hi,
Thank you so much for your reply. I am going to read the paper. However, if the increase in head size obscures the lGI, why this is not an overall variation? Meaning, why is only for the frontal and temporal lobes?
thank you
ines
On Tue, May 15, 2012 at 4:30 PM, j janssen joost.janssen76@gmail.com wrote:
Hi,
I am comparing a group of patients with controls. I extracted: cortical volume, surface area, cortical thickness and gyrification index for each subject's lobe. Comparisons between this variables with Total Intracranial Volume as a covariate indicated a difference in frontal and temporal lobes lGI.
what happens if you do not adjust for intracranial volume? if your patients have abnormal sized lobes then this may be obscured by controlling for head size.
However, differences were not significant for any of the other variables.
I can´t understand these results from a biological perspective. I was expecting that if a difference exist in lGI it would also manifest in surface area or volume.
this paper: http://www.ncbi.nlm.nih.gov/pubmed/18267953
tells us that it is possible for smaller sized brains to have higher folding compared to bigger sized brains. however, it also states that it's much more probable for bigger sized brains to have a higher degree of folding, indeed a strong relationship is shown between brain volume, cortical surface and folding (Figs. 3 and 4c) over large parts of the cortex.
hth, -joost
Can someone help me with an explanation for this?
Thank you.
ines
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.
freesurfer@nmr.mgh.harvard.edu
-
Inês Violante -
j janssen