cross-fiber

Hello
I’m trying to do a probabilistic tractography of the crossed fibers of the descending spinal cord pathways. I defined the ROI of the cerebral cortex on one side and the spinal cord on the opposite side. We analyzed a total of 19 dorsal trials, and in half of them, we found fibers passing through the cerebral beam (figure below). I defined the ROI of the cerebral cortex on one side and the spinal cord on the opposite side. We analyzed a total of 19 dorsal trials, and in half of them, we found fibers passing through the cerebral beam (figure below). I would like to know if this result is possible or if it is a probabilistic tractography over-analysis?
Thank you very much in advance!

Hi @1114,

This is an entirely common result with tractography (not even necessarily restricted to probabilistic and/or streamlines tractography). Obtaining a set of streamlines that reconstruct only a very specific pathway with no known false positives typically necessitates fairly extensive use of ROIs in order to preclude the reconstruction of such false positives, e.g. using the -exclude option.

Rob