Hi Allison, with very large changes across time, the longitudinal stream can fail or may need more manual intervention (edits). We have run it successfully on Huntington's Disease patients with large changes and many time points. The only way to find out if it works on your data is to run it.
I have recently made changes to the longitudinal stream (to be available in FS 5.2) that will allow inclusion of subject with a single time point. Currently we recommend to exclude them instead of running them as individual time points. The reason is that results in those cross sectional runs will be different from longitudinal runs and this may introduce a bias (especially if single time points subjects are more likely from one group than the other). Best, Martin On Thu, 2012-09-27 at 10:51 -0400, Allison Gruber wrote: > Hello, > > I am using the longitudinal processing stream to analyze a data set. I > have two questions: > > 1: We are expecting there to be significant changes in the volume of > certain structures and gray matter between time point 1 and 2. We > wanted to make sure the longitudinal stream is still appropriate. > > 2: If some subjects do not have both time points, should we process > them as individual time points or should we use a template brain in > order to use the longitudinal stream? > > Thank you very much, > Allison > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > _______________________________________________ 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.
