Hi Benjamin - This means that the initial guess for the path based on the atlas average is way off, due to poor alignment between your subject and the atlas subejcts. Ways to get around this is to look into the options for registration, whether diffusion-to-anatomical or anatomical-to-atlas, and to increase the number of control points used for fminor.

Hope this helps, a.y

On Mon, 6 May 2013, Roschinski, Benjamin wrote:

Dear Freesurfer experts,

we have a problem with the forceps. After the first trac-all we had a forcpes minor with a really unusually structure so we tried to fix it with an rerun of the trac-all. The result was a forceps minor with a third thigh in the sagittal axis. We did a second rerun and now the forceps minor normalized. Our problem is that we don´t know if we should do more trac-all reruns by other patients with difficult tracula or how we should interpret this result. Do you have any ideas to solve this? The second problem is that we have many many tracula results with incomplete forcepes minor or major. We know that the forcepes are the most difficult tracts because of the curvature but do you have some ideas to fix that problem?

Kind regards Benjamin

---

Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer