Dear List,
I'm using FSL to process a DTI data set acquired with 6 gradient directions + 1 b0, 4 repetitions. I eddy-correct them by coregistering all other images to first b0 image and then use bet to create brain mask. A 4d data set is then created by concatinating all images using avwmerge. Up to this point, everything seems to be fine, as I check the mask and 4d data using fslview. However, when I run dtifit as my last step, it processes as normal but the output isn't right as FA image is uniformly zero. Does someone have any idea what might wrong? The following is my bvec and bval file contents. I appreciate any comment!
bvec:
0.0000 0.7071 -0.7071 0.0000 0.0000 0.7071 -0.7071 0.0000 0.7071 -0.7071 0.0000 0.0000 0.7071 -0.7071 0.0000 0.7071 -0.7071 0.0000 0.0000 0.7071 -0.7071 0.0000 0.7071 -0.7071 0.0000 0.0000 0.7071 -0.7071
0.0000
0.0000 0.0000 -0.7071 -0.7071 -0.7071 -0.7071 0.0000 0.0000 0.0000 -0.7071 -0.7071 -0.7071 -0.7071 0.0000 0.0000 0.0000 -0.7071 -0.7071 -0.7071 -0.7071 0.0000 0.0000 0.0000 -0.7071 -0.7071 -0.7071 -0.7071
0.0000 0.7071
0.7071 0.7071 -0.7071 0.0000 0.0000 0.0000 0.7071 0.7071 0.7071 -0.7071 0.0000 0.0000 0.0000 0.7071 0.7071 0.7071 -0.7071 0.0000 0.0000 0.0000 0.7071 0.7071 0.7071 -0.7071 0.0000 0.0000
bval:
0 1000 1000 1000 1000 1000 1000 0 1000 1000 1000 1000 1000 1000 0 1000 1000 1000 1000 1000 1000 0 1000 1000 1000 1000 1000 1000
Regards,
Deqiang Qiu
