When i use amp2sh to construct SH and then reverse the operation with sh2amp, it seem that the diffusion sensitisation is flipped for the x-axis. I use a gradient file for the directions ([x,y,z]), when I adjust the directions to [-x,y,z] it seems I get nearly the same signal as in the original DWI volume. Am I doing something wrong, or is this maybe an inconsistency with FSL and MRtrix?
To know for sure, we would need to know exactly:
-
Where the diffusion gradients are obtained for the initial
amp2shcall; -
How you derive the external gradient file that you use for the
sh2ampcall; -
Which version of MRtrix3 you are using (particularly whether it is newer than this fix).