Did you check that the registration step worked properly? It may fail if, for example, you use a non-brain-extracted structural.
You can easily check this by applying the str2diff transform to your structural and loading the result in fslview together with an image in diffusion space.
On 15 May 2012, at 23:19, Chiara Pinardi wrote:
> I'm new with FSL and I have a problem with PROBTRACKX: I have to use a seed space that isn't diffusion, but structural. After the registration of DTI image on 3D with Fdt registration tool I select the transformation matrix 'str2diff.mat' (as Help says to do), but the 'fdt_paths.nii.gz' is still empty (the intensity is 0 everywhere) also when the seed size is very big and the paths chosen is very simple to elaborate (the same paths in diffusion space is drawn without problems).
> I don't understand where is the matter, so I hope that someone can help me with some advices!
> Sorry for my little English,
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