Dear FreeSurfer experts,

I am analyzing a dataset (Q-Ball) of subjects with TRACULA on FreeSurfer 6.0. b1=0, b2=3000 s/mm2 and diff directions = 90.

Surprisingly the trac-all  reconstruction with doeddy =1 was not as good as with doeddy = 0 on average on all the subjects, as in our dataset there were more tracts missing with doeddy=1 among all the subjects, which is a very curious result, shouldn't we get the reverse?

      ==> should I rely more on the doeddy=0 result then?

      ==> or should I modify the configuration parameters, such as adding more control points , ... and maybe others? 

Secondly, we are using the head motion parameters (computed with doeddy=1) to exclude subjects who moved too much. Is that appropriate? In other words, can we trust the motion parameters and exclude subjects on that basis?

Thank you for your time and consideration,

Sincerely,


Loic