The ISMRM 2015 Tractography Challenge

For references on the Tractometer, see the Tractometer references page for additional references to cite.

2023 Update paper

• Renauld, E., Théberge, A., Houde, J.-C., Descoteaux, M., Validate your white matter tractography algorithms with a reappraised ISMRM 2015 Tractography Challenge scoring system, Scientific Reports, 13:2347 (2023). Online Enhanced PDF, or Download PDF.
• Renauld, E., Théberge, A., Houde, J.-C., Descoteaux, M., Update of the ISMRM 2015 Tractography Challenge: curated data and enhanced Tractometer scoring system, ISMRM Workshop on Diffusion MRI: From Research to Clinic, October 2022.

Main ISMRM 2015 challenge papers

• Maier-Hein, Klaus H., et al. “ The challenge of mapping the human connectome based on diffusion tractography.” Nature communications 8.1 (2017): 1-13.
• The preprint version of the paper is available on BioRxiv.

Supplementary materials:

• Tractography Challenge ISMRM 2015: Supplementary figures and description of each submitted tractogram’s processing parameters.
• Tractography Challenge ISMRM 2015 Videos.

** See the tools page for links to the code.

Original references

For the sake of prosperity, we also leave here the main conclusions that were discussed during the challenge in 2015.

• Presentation done during the 2015-04-09 webinar.
• The results presentation document.
• Python2, deprecated version of the code of the scoring system for the ISMRM 2015 Tractography Challenge.

The last hour of the Diffusion Study Group of the ISMRM 2015 was dedicated to a discussion and debate on the open questions of tractography. Some of the main insights that were presented included:

• Generating streamlines that are perfectly voxel-aligned to the ground-truth anatomy is really challenging, in part because of the artefacts correction process. These corrections almost always add some shift with respect to the underlying anatomy.
• The previous point can have a huge impact in a pipeline that registers multiple subjects to a common template, for example for group studies.
• Scores are much better and more realistic when using a bundle recognition technique, instead of the classical Tractometer technique, which is based on endpoints.
• Most teams found 23 of 25 Valid Bundles, at the cost of generating multiple Invalid Bundles.
• Only one submission found the 25 Valid Bundles.
• The most difficult bundles were the Anterior Commissure and the Posterior Commissure.
• The main differences between pipelines are seen in the Invalid connections and the “No connections” (streamlines not connecting 2 regions).
• There needs to be a unified tractography format, to avoid potential interaction and interpretation problems.