Hi Alex I would think that longitudinal analysis is still the way to go as we try to improve both reliability and sensitivity using the fact that we have multiple scans/subject.
cheers Bruce On Tue, 3 Jun 2014, Alexandru Hanganu wrote: > Hello Everyone, > > could someone please give us an advice about which method you consider is > the best for our study ? > > we have two groups with MRI at Time 1. Each group received medication. After > this we performed another MRI at Time 2 after 2 weeks. > > The best method for this study is a longitudinal one or a cross-sectional > GLM ? > > We consider that the distance between the time points is too small, and the > longitudinal method is not the best choice. Hence, this study should be > treated as a cross-sectional one. In this case we think about performing a > simple GLM with the contrasts: > 0.5 0.5 0.5 0.5 > or 1 -1 -1 1 > > for the groups: > 1) grp 1 time 1 > 2) grp 1 time 2 > 3) grp 2 time 1 > 4) grp 2 time 2 > > we are searching to see whether medication had any impact on the cortical > morphology in each group and between the groups. > > Thank you ! > Best regards, > Alex. > > _______________________________________________ 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.
