ISMRM 2015 Tractography challenge - Discussion
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, using insights gained
from the results of the ISMRM 2015 Tractography Challenge.
Some of the main insights that were presented include:
- 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.
Please note that those results represent only a first analysis. The data provided by this challenge still holds troves of information. Further analyses will be done and communicated with the contestants and the community.
Go back to main challenge page.