If you are using --qcache, then there is nothing wrong specifically with the qdec implementation
On 10/13/2014 03:11 PM, Emma Thompson wrote:
Hi Anderson, Thank you for your paper. I guess I am confused. I have analyzed my structural data with qdec, specifically looking at a measure of cortical thickness and volume. I'm considering looking at surface area as well but was told it wasn't a very good measure using qdec, I have no other information really. Could you speak to whether or not this measure is valid in so far as one runs it using qdec?
Also, in your opinion, would it be redundant to look at surface area in addition to measures of cortical thickness and cortical volume?
Thanks for your help and apologizes for my silly questions.
On Sun, Oct 12, 2014 at 3:00 PM, Anderson M. Winkler <winkler@fmrib.ox.ac.uk mailto:winkler@fmrib.ox.ac.uk> wrote:
Hi Donna, In that same paper we also comment on the differences between expansion/contraction and absolute areal measurements assessed at each face of the surface (i.e., facewise), which can, after interpolation, be converted to vertexwise to facilitate analysis using current tools (e.g., mri_glmfit or qdec), without loss of areal quantities. All the best, Anderson On 11 October 2014 04:05, Donna Dierker <donna@brainvis.wustl.edu <mailto:donna@brainvis.wustl.edu>> wrote: Hi Emma, I might not be the only one who is unsure what you mean by a vertex-wise cortical surface area measure. Do you mean something like what is illustrated in figures 2 and 3 here: http://www.pnas.org/content/107/29/13135.figures-only … which is similar, but not identical to the local gyrification index? If so, would you use this measure on surfaces before or after registration to a target atlas? Donna On Oct 10, 2014, at 4:19 PM, Emma Thompson <voneconomos@gmail.com <mailto:voneconomos@gmail.com>> wrote: > Dear Freesurfers, > I recently heard that there are several disadvantages to using a measure of cortical surface area in Freesurfer, specifically due to conducting a vertex-wise analysis. Can someone help me understand why a measure of surface area using this approach might be flawed? Thanks! _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu <mailto: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 mailing list Freesurfer@nmr.mgh.harvard.edu <mailto: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.
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