Fit constraints 0,1,1 outputs implausible DTI FA maps

[rf2485]

Describe the Issue

Changing the default fit constraint from 0,1,0 to 0,1,1 removes the "salt and pepper" artifacts from my MK images and improves my KFA images. However, the FA images show poor contrast and abnormally high values in the gray matter and CSF.

Issue Reproduction

pydesigner -s --fit_constraints 0,1,1 --verbose -o pyd_out rawdwi.nii.gz

Supplemental Information

FA 0,1,0 (default)

FA 0,1,1