Dear Freesurfer experts,
I am attempting to do a longitudinal analysis of cortical thickness with 3 timepoints. So far, I have successfully completed the analysis for long_mris_slopes comparing timepoint 1 to timepoint 2, timepoint 2 to timepoint 3, and a linear increase for timepoint 1 to 2 to 3.
However, I am primarily interested in finding regions which show a) an increase between timepoint 1 and 2, but no difference between 2 and 3, and b) no difference between timepoint 1 and 2, but an increase between 2 and 3.
Would the correct way of 'modelling' these two in the qdec file be:
a) fsid fsid-base years day1 base 0 day2 base 3 day3 base 3
and b) fsid fsid-base years day1 base 0 day2 base 0 day3 base 3
All the best, Jodie
- --- Jodie Davies-Thompson, Postdoctoral Fellow Department of Ophthalmology & Visual Sciences UBC/VGH Eye Care Centre 2550 Willow Street Vancouver, BC, V5Z 3N9 Canada Tel: 604-875-4111 ext 69003