Hi Greg, I would say there are a variety of possible confounds for cortical thickness (e.g. changes in cortical myelin content, changes in the closeness of opposition between grey matter and the dura from brain atrophy), but that wouldn't be one of the ones I would think of. White matter hyperintensities tend to be most visible in T2w images (especially FLAIR), and not so much in T1w images (in fact, they might actually make T1w images darker). They also tend to be in deep white matter away from the cortex.
The insula tends to be a hard place to reconstruct surfaces because the white matter is thin and not very bright (and has the grey matter claustrum interposed between the external and extreme capsules). A difference in the white matter or claustrum could well create a problem reconstructing the surface there, but I wouldn't expect a white matter hyperintensity there. Peace, Matt. -----Original Message----- From: freesurfer-boun...@nmr.mgh.harvard.edu [mailto:freesurfer-boun...@nmr.mgh.harvard.edu] On Behalf Of Gregory Kirk Sent: Wednesday, April 04, 2012 11:47 PM To: freesurfer@nmr.mgh.harvard.edu Subject: [Freesurfer] white matter hyper intensities a collaborator just got a grant review that claimed There's a possibility that changes in cortical thickness in the insula might be a consequence of lesions (MR-hyperintensities) in the white matter. i would think that white matter hyper intensities would tend to enhance freesurfers ability to detect the white matter/grey matter boundary rather than cause an error. any comments as to the correctness of my thinking would be appreciated. thank you greg _______________________________________________ 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 mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
