Dear FSL experts,
I ran TBSS analysis using FA maps to check the difference in FA values between two groups ( 16 patients and 12 controls). I followed the guide http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/TBSS/UserGuide
In order to study the difference between the groups in FA values. I ran the following two commands inside the folder stats
design_ttest2 design 16 12
randomise -i all_FA_skeletonised -o tbss -m mean_FA_skeleton_mask -d design.mat -t design.con -n 5000 --T2 -v 3
The analysis ran smoothly without any troubles. The statistical map of interest is (tbss_tfce_corrp_tstat2.nii.gz) which represent patients < controls.
Now I wanted to use the script "tbss_sym" to study the difference in FA between left and right hemispheres between the groups
Inside the folder stats I ran the command "tbss_sym FA". This created the following new files:
mean_FA_symmetrised.nii.gz
all_FA_skeletonised_left_minus_right.nii.gz
all_FA_symmetrised_skeletonised.nii.gz
mean_FA_symmetrised_skeleton.nii.gz
mean_FA_symmetrised_skeleton_mask.nii.gz
mean_FA_symmetrised_skeleton_mask_dst.nii.gz
In order to investigate the difference in FA values between left and right hemispheres in patients as a comparison with controls. I ran the following command inside the folder "stats":
randomise -i all_FA_skeletonised_left_minus_right.nii.gz -o tbss_LR -m mean_FA_symmetrised_skeleton_mask.nii.gz-d design.mat -t design.con -n 5000 --T2 -v 3 ( design .mat and design.con are the same in the previous command)
Kindly, is this command correct?
If I want to study the difference in FA values between right and left hemispheres in patients as a comparison with controls.
I flipped the file "all_FA_skeletonised_left_minus_right.nii.gz" using "flip4fsl", and I flipped the mask "mean_FA_symmetrised_skeleton_mask.nii.gz" using the same command "flip4fsl", then I ran randomise on the resultant images ( same contrasts)
Kindly, Are these steps correct? Thank you very much for your help
Jon
|