Hi Emily it is a segmentation error, but it's a pretty small one. It will mess up the thickness in a region a few mm^2. You could fix it by editing the wm.mgz if you really care about that spot
cheers Bruce On Wed, 21 Feb 2018, Emily Schwartz wrote: > Hi Doug, > > Thank you for getting back to me. I've attached two images (Slice165 and > Slice166) with an arrow pointing to the location. I am new at this, so maybe > I am wrong and it is not a segmentation error. > > I've also attached an additional image (Slice185) of what I think is a type > of topological error that I often see multiple times in a subject. Is this a > topological defect? If so, if it is only over 3 slices does it need to be > corrected? > > Thanks again, > > Emily > ________________________________ > From: freesurfer-boun...@nmr.mgh.harvard.edu > [freesurfer-boun...@nmr.mgh.harvard.edu] on behalf of Douglas N Greve > [gr...@nmr.mgh.harvard.edu] > Sent: Tuesday, February 20, 2018 4:59 PM > To: freesurfer@nmr.mgh.harvard.edu > Subject: Re: [Freesurfer] Surface Errors > > sorry, what kind of errors? I could not really tell from the images what > the problem was > > > On 02/20/2018 10:22 AM, Emily Schwartz wrote: >> Hi FreeSurfer community, >> >> I am working on elderly subjects and have had this kind of surface error >> quite often in different locations. Usually, it's over about 3-4 slices (in >> one view) and can be fixed, but I am finding multiple in almost every >> subject and therefore taking a lot of time to edit (and then once >> reprocessed new ones sometimes come up in different locations). I was >> wondering if these are normal to have, minor surface errors that do not >> necessarily need to be fixed. I have added images of an example below. Here >> are some of the values I get from aparc.stats for caudal middle frontal lh >> after manually editing: >> >> Surface area: >> Original - 2500 mm^2 >> Edited - 2532 mm^2 >> >> Grey volume: >> Original - 1710 mm^3 >> Edited - 1727 mm^3 >> >> Thickness avg >> Original - 4455 mm std: 2.371 >> Edited - 4445 mm std: 2.365 >> >> Although the thickness values only differ by 10 mm, we are a little >> concerned because the difference is not within the standard deviation. >> >> Please let me know if all of these errors should be edited or if it may be >> okay to keep the smaller segmentation/topological errors as they are. >> >> Thank you, >> >> Emily >> >> >> >> >> _______________________________________________ >> Freesurfer mailing list >> Freesurfer@nmr.mgh.harvard.edu >> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > -- > Douglas N. Greve, Ph.D. > MGH-NMR Center > gr...@nmr.mgh.harvard.edu > Phone Number: 617-724-2358 > Fax: 617-726-7422 > > Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting > FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 > www.nmr.mgh.harvard.edu/facility/filedrop/index.html > Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/ > > _______________________________________________ > 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
