Dear FSL users,
I am using tractography to get the track from one seed mask to one target mask. Now I wanna extract fa value from the track. In order to ensure the results are restricted to white matter regions, I also want to constrain fa value to 0.2. What's difference between these following two approaches?
1. obtain a mask by constraining fa value of 0.2 first:
fslmaths <FA> -thr 0.2 -bin -sub 1 -mul -1 <stopmask>
And then use <stopmask> as a stopmask in probtrackx. (but in this case, if I already have one target mask, how can I use this FA stopmask as target mask?)
Next to extract fa value from the track created by the last step.
fslstats dti_FA.nii -k track.nii -M
2. extract fa value from the track (not using restricted FA mask as stopmask) and directly constrain using FA of 0.2
fslstats dti_FA.nii -k track.nii -l 0.2 -M
What are the underlying differences and which one is more appropriate?
Thanks a lot.
Best regards,
Lijun Yin
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