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Hi Anderson, In our preliminary analysis, I used 4D image of t2-t1 or t3-t1 and radomise analysis. I wonder how different between radomise and palm NPC analysis? Best regards, Yawu 2018-01-14 21:57 GMT+02:00 Anderson M. Winkler <[log in to unmask]>: > Hi Yawu, > > Probably the safest approach is to do compute t2-t1 for each subject who > has both timepoints, and also t3-t1 for each subject, and do a simple > 2-group comparison (as in a two-sample, unpaired t-test) using either > MANOVA or NPC, the latter having the advantage of being more powerful and > allowing for directional effects. In PALM you'd run as this: > > *palm -i diff_t2-t1.nii -i diff_t3-t1.nii -d design.mat -t design.con -npc > -n 5000 -approx tail -nouncorrected -o myresults -logp* > > > It is also possible to do a 2x3 repeated measures ANOVA, assuming compound > symmetry between all three timepoints. In that case, please see a design > here: https://s3-us-west-2.amazonaws.com/andersonwinkler/mailingli > st/design_yawu.ods > All timepoints would be used. PALM would be invoked as this: > > *palm -i all_timepoints.nii -d design.mat -t design.con -f design.fts -n > 5000 -approx tail -nouncorrected -o myresults -logp* > > > Hope this helps! > > All the best, > > Anderson > > > On 26 December 2017 at 03:34, Liu Y <[log in to unmask]> wrote: > >> Hi Anderson, >> We are interested in the difference among the three time points in each >> group, and also the difference in DTI change between two groups. >> Best regards, >> Yawu >> >> >> 2017年12月26日 06:35，"Anderson M. Winkler" <[log in to unmask]>写道： >> >> Hi Yawu, >> >> Are you interested in differences between timepoints and whether these >> differ between groups, or are you interested on the average between >> timepoints and whether these differ between groups? Or are you interested >> in something else? >> >> All the best, >> >> Anderson >> >> >> On 21 December 2017 at 03:21, Liu Y <[log in to unmask]> wrote: >> >>> >>> Dear Experts, >>> >>> We have 2 groups, three time-points: how to model all time-points within >>> a single design given that not all subjects have second or third time-point >>> measurements, and take into account baseline differences in DTI metrics. >>> Any suggestions are highly appreciated. >>> >>> Best regards, >>> Yawu >>> >>> >>> >>> >>> >> >> >