Tckgen - parameters for interhemispheric connections

[imagingBrains]

Hi!

I’ve been investigating interhemispheric and intrahemispheric long-range connections from several lateral occipital and temporal ROIs, and I’m noticing that the projections often appear quite diffuse. For example, when looking at the endpoints of a lateral occipital seed on the lateral surface of the opposite hemisphere, the resulting connections tend to be scattered and patchy. The same holds for connections to frontal and parietal regions even in the same hemisphere.

Here’s an example with endpoints of left MT on the left hemisphere, and endpoints of right MT on the left hemisphere showing the patchy and diffuse connections.

I’ve experimented with both angle and maxlength, but neither seemed to substantially improve the tractography results. I’d be really interested to hear any recommendations for optimizing tracking of interhemispheric connections or general strategies you’ve found helpful in similar cases.

Thanks a lot in advance, and thanks for the awesome software!

[John_Broulidakis]

I’m interested in what you find.

May I ask:

How many streamlines are you currently generating with tckgen?

Have you tried varying this number and plotting how increasing the streamline count influences the result

It might be interesting to plot this as a histogram — for example, showing the number or proportion of connections detected as a function of streamline count.