Hello FSL/probtrackx experts,
I am trying to use DTI data and FSL's probabilistic tractography tool (probtrackx2) to establish the presence/absence of connectivity between various pairs of brain ROIs ( includes white matter and gray matter). I am unable to find any reference on what establishes connectivity between two regions.
Is there a commonly followed default threshold, which needs to be met to say two regions are connected? For example, for a seed ROI with 100 px, at the default sampling rate of 5000 samples/px, this yields up to a maximum possible 500,000 tracts (can be obtained from the waytotal file). Currently, I'm following a rule that at least 0.01% of the total number of tracts (50 in this case) need to reach a target ROI in order to say that the seed and target ROIs are connected. Is this an acceptable threshold? I'd really appreciate your thoughts and suggestions as well as any papers that reference the same.
Thanks,
/Suraj
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