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Mapping the human connectome : a challenge to the scientific community of diffusion imaging and tractography


​Mapping the human "connectome" requires identifying the anatomical connections made by the white fibers. A NeuroSpin researcher (GIN / Bordeaux) participated in a large study involving 20 Research Teams, with the aim of providing the best possible reconstruction of anatomical connectivity of the human brain with tractography procedures. The results of this study, published in Nature Communications, show the limitations of tractography and should favor the development of new algorithms.

Published on 4 December 2017

Abstract

Tractography based on non-invasive diffusion imaging is central to the study of human brain connectivity. To date, the approach has not been systematically validated in ground truth studies. Based on a simulated human brain data set with ground truth tracts, we organized an open international tractography challenge, which resulted in 96 distinct submissions from 20 research groups. Here, we report the encouraging finding that most state-of-the-art algorithms produce tractograms containing 90% of the ground truth bundles (to at least some extent). However, the same tractograms contain many more invalid than valid bundles, and half of these invalid bundles occur systematically across research groups. Taken together, our results demonstrate and confirm fundamental ambiguities inherent in tract reconstruction based on orientation information alone, which need to be considered when interpreting tractography and connectivity results. Our approach provides a novel framework for estimating reliability of tractography and encourages innovation to address its current limitations.

Read the French version.

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