Seeking Guidance on Generating a Global Value for FA Map using tckmap

Dear MRtrix3 Community,

I’m currently working on generating a global value for a FA map and would like to seek your advice on the process I’ve used so far.

First, I conducted whole-brain streamline tractography and transformed the resulting full set of streamlines into a whole-brain density image using ‘tckmap’. I incorporated SIFT2 weights into this computation to downweight any spurious fibers. Here’s the command I used:

tckmap -template dwi_proc_b0.nii -tck_weights_in tracks_10M_sift2_weights.txt tracks_10M.tck output.TDI.nii

Subsequently, I multiplied output.TDI.nii by the subject-specific proportionality coefficient (mu) to ensure valid group-level comparisons. The resulting track-weighted image was then used to weigh (multiply) each DTI metric map (FA, MD), which was followed by averaging within the white matter mask.

My question centers around the validity of this approach. I appreciate any feedback or suggestions!

Thank you in advance.

Best regards,

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