Hi,
I am using dtifit to generate FA maps to be able to run TBSS.
The FA maps generated are all voxels with a value of 1, but the MD maps seems fine.
I am using the following command line:
dtifit -k data.nii.gz -o dti -m mask.nii.gz -r bvecs -b bvals
My data.nii.gz is a 4D file, eddy corected, 31 volumes, 1st volume is the b0 and the others the 30 directions.
My mask is a standard binarized mask with only 1 and 0.
bvals = 0 1000 1000 1000 ... (30x1000)
My bvecs is most likely my problem, it is a standard 3x31 values, but all the values from one line after the 0 are the same: e.g.:
0 -0.998676 -0.998676 -0.998676 -0.998676...
0 0.041493 0.041493 0.041493 0.041493...
0 -0.0304004 -0.0304004 -0.0304004 -0.0304004...
I tried different dicom to nifti software to convert my dicom files, but the bvecs files are always like that.
Any idea what might went wrong?! And if my bvecs file is not the problem, what can cause the all 1s FA map?
Thanks a lot.
Pascal
Pascal Tétreault, Ph.D
Postdoctoral fellow
Dr. Christian Beaulieu's lab
Biomedical Engineering, Faculty of Medicine
University of Alberta
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