Added fixelcsa, a command to compute the change in fixel cross-sectional area during spatial normalisation. Used for FBM. Currently inputs the jacobian image, however this will eventually be changed to input the combined affine and warp field image
Added fixelcsa, a command to compute the change in fixel cross-sectional area during spatial normalisation. Used for FBM. Currently inputs the jacobian image, however this will eventually be changed to input the combined affine and warp field image

MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3