Hi FSL group,
I want to complete tractography in an eye-movement network with 16 ROIs. I'm interested in the pairwise connections between each ROI pair (ex. ROI_1 -> ROI_2, ROI_1 -> ROI_3, etc) and obtaining a measure of FA as well as the trajectory between each ROI pair. So I started out with using ROI_1 (ex- left preSMA) as a seed mask and ROI_2 (ex- right preSMA) as a waypoint. When I did this there were tracks that went through the corpus callosum as expected. However, I noticed that there were tracks that went beyond the right preSMA and tracks that seemed to connect at the very top portion of the brain not using the corpus callosum. Since I didn't want it to extend past ROI_2 I also put ROI_2 as a termination mask. This seemed to solve that problem. However, there still seems to be a good number of tracks that connect the right and left preSMA that don't go through the corpus callosum but at a higher level of the brain, which doesn't seem anatomically possible.
1) Why is this happening?
2) Is there a way to stop this from occurring and to get a track that ONLY goes from ROI_1 to ROI_2 and vice versa?
Your help would be greatly appreciated!