Hello FreeSurfers and TRACULA expert,
I would be grateful if anyone could help me with my problem:
I was able to run all the steps of TRACULA on several subjects without any error message. My problem is that the average FA/MD/RD/AD outputs are not in the same range as previous studies. For example, the average FA values for all the tracts are between 0.6 and 0.8, which I think is too high - especially since my population are elderly adults. I wonder if anyone else had the same issue and if anyone can help me what might be the source of the problem.
While I was trying to narrow down the possible sources of error, I reran a couple of subjects registering with both "FLIRT" & "bbregister". I think in the latest version of tutorial "bbregister" is the preferred method. The results show very large differences between the 2 methods! Is this expected &/ normal? Although these are different from each other, both of them still are out of range (i.e. average FA value 20% more than literature), so registration method -alone- is not the source of my 1st problem.
Thank you so much, Ali