The evaluation of analysis methods for diusion tensor imaging (DTI) remains challenging due to the lack of gold standards and validation frameworks. Signicant work remains in developing metrics for comparing ber bundles generated from streamline tractography. We propose a set of volumetric and tract oriented measures for evaluating tract dierences. The dierent methodsdeveloped for this assessment work are: an overlap measurement, a point cloud distance and a quantication of the diusion properties at similar locations between ber bundles. The application of the measures in this paper is a comparison of atlas generated tractography to tractography generated in individual images. For the validation we used a database of 37 subject DTIs, and applied the measurements on ve specic ber bundles: uncinate, cingulum (left and right for both bundles) and genu. Each measurments is interesting for specic use: the overlap measure presents a simple and comprehensive metric but is sensitive to partial voluming and does not give consistent values depending on the bundle geometry. The point cloud distance associated with a quantile interpretation of the distribution gives a good intuition of how close and similar the bundles are. Finally, the functional dierence is useful for a comparison of the diusion properties since it is the focus of many DTI analysis to compare scalar invariants. The comparison demonstrated reasonable similarity of results. The tract dierence measures are also applicable to comparison of tractography algorithms, quality control, reproducibility studies, and other validation problems.
['Sylvain Gouttard', 'Casey Goodlett', 'Marek Kubicki', 'Guido Gerig']
Measures for Validation of DTI Tractography.