I am not quite sure what you are doing, but I suspect the best thing
to do would be to use carefully-placed waypoint masks to identify the
different pathways of interest.
For example, if you include a waypoint mask in the Arcuate
fasciculus, this will certainly get rid of U-fibres.
Cheers
T
On 1 Jul 2008, at 14:41, Anastasia Ford wrote:
> Hello,
>
> I am trying to map the white matter bundles originating in Broca's
> region
> (44/45). I have tried different ways to map these projections, but
> in all
> cases it seems that the tracing algorithm picks up the fibers from the
> regions adjacent to the mask.
> I have used probabilistic tissue-type segmentation on the T1 to
> select only
> voxels that have probability of being >40% grey matter. I also
> tried similar
> approach using a diffusion mask, using only the voxels that have FA
> values
> of 0.2-0.3 within the Broca's region. In all of the cases, there
> are many
> paths with high probabilities located in the regions adjacent to
> the Broca's
> region. I am assuming that the U-fibers running from the Broca's
> region to
> the adjacent cortical zones are causing these problems.
> Do you have any advice on what would be the best way to prevent the
> interference from the neighboring regions?
> Thank you for your help.
>
>
> Sincerely,
>
> Anastasia
>
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