Dear K,
> I am looking at some DTI data in TBSS. I followed tbss_2_reg and
> tbss_3_postreg scripts to transform the data to MNI space. After
> looking at all_FA.nii I noticed some significant banding distortion
> in a number of the images, though the alignment it self looks to be
> ok.
> Any idea what could be causing these problems? They are present in a
> lot of the participants volumes and I'm worried they are
> significantly impacting results (though perhaps the skeleton
> minimizes their contribution somewhat).
> Note I was aligning to the standard template. I've attached an
> example image to this message
I have noticed these in the past as well, and in those cases they have
been caused by slice-wise signal variations that fnirt then rotated
away from the plane and into these diagonal bands. Can I ask you to
first of all go back to your original image and see if you can
identify them there? They are much less conspicuous when running
parallel with the planes.
Jesper
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