Hi Mojdeh it's really hard to say how much you should correct. In general we don't do that much. A couple of control points or a few voxels added to the wm.mgz can have a big effect if you are experienced. Mostly just see if the ?h.white and pial surface are visually accurate, and if not see if some small intervention might fix them.
cheers Bruce On Fri, 20 Jul 2012, Mojdeh Zamyadi wrote: > Hi Bruce, > > Thank's for the reply! I'm not concerned about hippocampal volume for now, > mostly needing cortical thickness for my project! Yes, I am using v5.1. So in > case of cortical thickness I shouldn't worry too much about Talairach > registration? could you please tell me what are the main things I should > check and pay attention to for cortical thickness? I'm following the > troubleshooting page > (http://surfer.nmr.mgh.harvard.edu/fswiki/RecommendedReconstruction) and I > see some discrepancies in the pial/WM surfaces but again I am not sure how > much I should correct! > > Thanks again, > -Mojdeh > > On 07/20/2012 04:15 PM, Bruce Fischl wrote: >> Hi Mojdeh >> >> it won't affect any individual thickness measures, *but* will affect the >> estimated total intracranial volume (eTIV). We don't typically use eTIV for >> thickness correction, but do for things like hippocampal volume. Are you >> using version 5.1? If so, that's the problem. Nick has a fix for this that >> he can direct you about, or you can wait for 5.2 and rerun the Talairach >> registration then. >> >> cheers >> Bruce >> >> >> On Fri, 20 Jul 2012, Mojdeh Zamyadi wrote: >> >>> Hi all, >>> >>> Sorry for re-posting this but it seems it didn't get through! >>> >>> I've just started to do cortical thickness analysis on some subjects and >>> I'm noticing some miss-registrations, more specifically the Talairach >>> image is smaller than the target image no matter what subject I look at! >>> I just wanted to make sure if this is something normal and to what >>> extend it's going to effect the individual cortical thickness >>> calculations. I guess I'm not sure how the Talairach transformation is >>> used in further steps of the cortical thickness calculation. >>> >>> I tried to attach example coronal, sagittal and horizontal slices of one >>> of my subjects but apparently it was too big for the mailing list. Pleas >>> let me know if there is a way to attach images here. >>> >>> I greatly appreciate your advice. >>> >>> Thanks, >>> Mojdeh Zamyadi, MSc >>> Clinical Research Project Assistant >>> The Hospital for Sick Children >>> 555 University Avenue >>> Toronto, ON, M5G 1X8 >>> _______________________________________________ >>> 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
