Hi, I noticed after I did the procedure with the recent donated script to
rotate the gradient while doing eddy-current correction (i.e eddy_correct
dti data 0 bvecs), when I run the data in DTIFIT, the output ADC image has
range of intensities including-ve values. In the ADC output from dtifit
without rotatating gradients prior, the range is from 0 to positive.
If the gradients are rotated, why would that caused the output ADC map
from DTIFIT to have negative values? Would these new negative values
matter in the other analysis that will be done i.e registration etc, and
if I should remove these negative values with fslmaths dti_MD.nii.gz -max
0 newdti_MD.nii.gz (The negative values are mainly in the extreme
peripheries of the brain/nonbraintissues). its of values 0.007 and less.
Thanks
Siewmin
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