Hello Matteo,
can you maybe be a bit more precise and tell me what you mean by saying that your fibres went widespread in different directions? It would be great if you could attach some images with the ROIs and the tractography results.
After processing your diffusion data with Bedpostx, did you try to visualise the dyadic vectors on top of, e.g., the FA mask, to check if the mean direction looked fine?
Which parameters did you use for Bedpostx?
Cheers,
Matteo
> On 5 Feb 2015, at 14:58, Matteo Martino <[log in to unmask]> wrote:
>
> Hello!
>
> We are new users of FSL.
>
> We performed the probabilistic tractography with probtrackx after the bedpostx processing. We would like to perform the structural connectivity on the basis of the functional connectivity. First, we constructed 2 masks. We constructed 2 ROI (sphere of 6 mm of ray around a specific coordinate) that we found to be hypoconnected in FC in a previous analysis on the same sample. We co-registrated these ROI in the MNI152_T1_2mm. We binarized the 2 masks. We could correctly visualize the 2 masks in flsview. Then, we did probtrackx by using the first mask as seed space (using standard2diff.mat) and the second mask as termination mask (we did not change all the other options, which remained standard). We obtained the typical four files and visualized fdt_paths.nii.gz on flsview. Since the two regions are in the anterior cingulum and in the posterior cingulum, respectively, we supposed that the pathways should run in the cingulum bundle. However, the pathways started from the seed mask but did not reach the termination mask and went widespread in different directions.
>
> Can you help us?
>
> Thank you very much!
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