Hi Shannon, that cannot be. It either indicates a serious bug (which we have not yet encountered in our data) or a problem with your processing.
Can you send me: - the version you use - the command line you run - the output you get Also long_mris_slopes is designed for analyzing surface maps (analysis on a vertex by vertex basis). This is usually thickness. So I don't understand what 'volumes' you mean? For an ROI analysis based on stats files you need to use long_stats_slopes. Best, Martin On Thu, 2012-09-27 at 11:37 -1000, Shannon Kogachi wrote: > Hi Martin, > Each subject has 3-6 timepoints. They are all about one year apart. > Here's an example of the discrepancy: one subject with 5 timepoints > had volumes that ranged from 2.2-2.4. However, from the > long_mris_slopes command, the temporal average volume was calculated > to be 1.67. Thanks for your help! > > -Shannon K. > > On Thu, Sep 27, 2012 at 6:21 AM, Martin Reuter > <mreu...@nmr.mgh.harvard.edu> wrote: > Hi Shannon, > > long_mris_slopes works for surface maps (both thickness and > volume > should work). In both cases it should compute the temporal > average. > > I have another scripts that works for stats files > (long_stats_slopes) in > the same way. > > How many time points do you have, how far apart (equally > spaced?). > > Best, Martin > > On Wed, 2012-09-26 at 14:59 -1000, Shannon Kogachi wrote: > > Hi Martin, > > When I used the long_mris_slopes command for the > thickness, the > > average thickness calculated in FreeSurfer was pretty > similar to > > averaging the values in FreeSurfer. Does this command only > work > > thickness measures and not for volume or area? Thanks! > > > > -Shannon > > > > On Wed, Sep 26, 2012 at 2:49 PM, Martin Reuter > > <mreu...@nmr.mgh.harvard.edu> wrote: > > Hi Shannon > > > > You probably mean average thickness. > > My scripts compute the temporal average from the > linear fit > > (at mid time), which can be differed from simply > averaging > > values. > > Best Martin > > > > Shannon Kogachi <skoga...@gmail.com> wrote: > > Hi, > > I had a question about how the temporal > average is > > calculated for subjects with multiple > timepoints. I > > used the long_mris_slopes command on a > longitudinal > > set of data. However, when I compared the > average > > volumes calculated through this command to > the average > > volumes calculated in excel after extracting > the same > > vertices at the individual timepoints, these > values > > did not match up. The average volumes > calculated > > through long_mris_slopes were smaller. > Please let me > > know if there is a way to explain this > discrepancy. > > Thank you! > > > > -Shannon K. > > > > > > > > > > ______________________________________________________ > > > > Freesurfer mailing list > > Freesurfer@nmr.mgh.harvard.edu > > > > > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > > > -- > > Sent from my phone, please excuse brevity. > > 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
