Dear FSL users,
I am trying to use FSL-VBM v1.1 on two groups of subjects (young vs old) to
look at effects of ageing in GM. The VBM output revealed some strange results -
highly significant clusters of voxels (showing decrease of GM with age)
within white matter areas (attached snapshot). Do you have any idea what
could possibly be the reason for these ambiguous results?
Here are the steps I have done:
- individual BET with varying -f and -c option to provide proper brain
extraction
- fslvbm_2_template -n
- fslvbm_3_proc 0.2
- randomise -i GM_mod_merg_s4 -o GM_mod_merg_s4 -GM_mask -d design.mat -t
design.con -n 5000 -tfce(-c 3) -V
- the design was created in the Glm wizard with two contrasts (A>B: 1 -1;
B>A:-1 1)
- the attached snapshot shows the GM_mod_merg_s4_tfce_corrp_tstats1
(intensity threshold 0.999-1) overlaid on the standart MNI152_2mm
Any suggestions are greatly appreciated.
thanks,
Kosta
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