Hi Alejandra, I don't work with children, so I'll let someone else (Lilla? Rudolph?) answer. doug ps. Please remember to copy the list on responses. Thanks!
On 05/08/2013 01:19 AM, Alejandra Infante wrote:
Thank you! I might have asked this at the training, but I am still not clear on whether the estimated ICV (from freesurfer) is reliable if your population of interest are children? Or would you recommend manual edits (when needed) after checking the quality of the talairach registration file using tkregister2 --s subjid --fstal --surfs?
On Tue, May 7, 2013 at 7:52 PM, Douglas Greve <greve@nmr.mgh.harvard.edu mailto:greve@nmr.mgh.harvard.edu> wrote:
It is neither:) See http://surfer.nmr.mgh.harvard.edu/fswiki/eTIV and/or Buckner et al. (2004) NeuroImage <https://surfer.nmr.mgh.harvard.edu/fswiki/NeuroImage> 23:724-738. "Basically, total intracranial volume is found to correlate with the determinant of the transform matrix used to align an image with an atlas. The work demonstrates that a one-parameter scaling factor provides a reasonable TIV estimation. This method uses an atlas based spatial normalization procedure, and requires that the *talairach.xfm* is correct. " This performs the talairach registration for a subject. Then, based only on the numbers in the matrix, it estimates the ICV based on subjects that had similar matrices. doug On 5/7/13 9:42 PM, Alejandra Infante wrote:Hi, I understand that ICV is an estimated measure based on a standard talairach transformation; however, I want to know how freesurfer is defining intracranial volume (i.e., is this a representation of everything within the cranium as the name implies or is it an estimate of total brain volume, which would not include space between skull and dura)?. We are using fs vesion 5.1 -- M. Alejandra Infante Doctoral Student SDSU/UCSD Joint Doctoral Program in Clinical Psychology Phone: (858) 449-2950 <tel:%28858%29%20449-2950> E-Mail: infante.alejandra.m@gmail.com <mailto:infante.alejandra.m@gmail.com> _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu <mailto:Freesurfer@nmr.mgh.harvard.edu> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer_______________________________________________ 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.-- M. Alejandra Infante Doctoral Student SDSU/UCSD Joint Doctoral Program in Clinical Psychology Phone: (858) 449-2950 E-Mail: infante.alejandra.m@gmail.com mailto:infante.alejandra.m@gmail.com