Hi, Talairach.xfm is a text file which contains a transformation matrix. Though there is small numerical difference between two transformation matrix made using mritotal and the default Talairach registration. The process of calculation the ICV may amplify this difference since it used the determinate of the transformation matrix to calculate ICV. The differences in ICV may depend on how different the numerical values of the Talairach transformation matrix are.

Best regrards Knut J

On 12/14/2012 09:06 PM, Eric Cunningham wrote:

Hi,

this link: http://surfer.nmr.mgh.harvard.edu/fswiki/TalFailV5.1 discusses a solution to bad talairach.xfm transforms, the -use-mritotal flag.

this link: http://surfer.nmr.mgh.harvard.edu/fswiki/eTIV mentions that the talairach.xfm is used to calculate the total intracranial volume.

is using mritotal likely to result in significantly different intracranial volumes even if the talairach.xfm does not appear to be very different when viewed?

thanks much, -eric

---

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.