Investigating connectivity, the thorn in the side of diffusion imaging.

Diffusion Magnetic Resonance Imaging (dMRI)-based tractography is increasingly used in both medical and research settings to investigate the network of the brain. Yet, only a handful of studies have attempted to compare it to the ground truth of tract tracing results. We recently started our own investigation of the question, using our extensive database of tract-tracing connectivity. We show that there are important issues with the method of tractography, issues that, if not properly addressed and solved, could compromise the future of this tool in investigating cortico-cortical connectivity.