Hi Charlie
You can use fslswapdim to reorient the data and reverse a certain axis. You then need to swap the sign in the respective coordinate of the bvecs vectors. An easy way to double check things have worked out correctly is to run dtifit, have a look at dti_V1 through fslview and make sure that the fibre orientations (e.g. in the corpus callosum) make sense within all planes.
Cheers
Stam
On 26 Jan 2014, at 18:03, charlie Leger <[log in to unmask]> wrote:
> Preprocessing for a TBSS asymmetries test revealed one participant’s diffusion data has a different orientation (reversed). I assume that, unlike anatomical T1 scans, diffusion-weighted data can’t be corrected at the outset (e.g. dcm2nii –r y file.nii) because the diffusion directional information would not change in tandem with the newly reoriented image, which would disrupt directional information (e.g. FA). Is this correct or can this participants diffusion data set reoriented to be consistent with the other diffusion-weighted data sets.
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> Any feedback would be greatly appreciated.
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> Charlie
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