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Dear Maria, to create your customized template it's sufficient to include only the first scan of every subject. Even if you have an adult population I would recommend to create your own template, because not only the sample influences your template, but also the MR scanner/sequence (e.g. differences in contrast between tissues, nonuniformities, scanner/sequence specific distortions ...). However, to preprocess longitudinal data there are some more steps necessary to perform a good realignment between the timepoints and - more important - to estimate spatial normalization parameters only from the first scan, but to apply these parameters to all subsequent scans. If you estimate normalization parameters for each scan separately you might diminish meaningful differences between the scans. You can find a tool to preprocess longitudinal data at: http://dbm.neuro.uni-jena.de/cg_vbm_longitudinal.m Best regards, Christian PS: To analyze longitudinal data I recommend the PET models Multi-subjects (or Multi-groups): conditions & covariates. ____________________________________________________________________________ Christian Gaser, Ph.D. Department of Psychiatry Friedrich-Schiller-University of Jena Philosophenweg 3, D-07743 Jena, Germany Tel: ++49-3641-935805 Fax: ++49-3641-935280 e-mail: [log in to unmask] http://dbm.neuro.uni-jena.de On Wed, 5 Jan 2005 15:00:29 -0500, Maria Densmore <[log in to unmask]> wrote: >Hello, > >I would like to run the optimised VBM spm2 analysis on one patient group which >was scanned at three time points, to look at any change in volume between time >periods. Would I include all three scans for each subject in the template >creation? > >If I have an adult population is it necessary to create my own template? > >Thanks for your time, > >Maria > > > >_____________________________________ > M. Densmore, Image Analyst > Lawson Research Institute > St. Joseph's Health Centre > 268 Grosvenor Street > London, Ont. N6A 4V2 > > [log in to unmask] > office: (519) 646 6100 ext 64864 > fax: (519) 646 6399 >_____________________________________