Probabilistic Tractography of Key Language Tracts: MNI-based Spherical ROIs Improve Sensitivity and Specificity

Motivation: Pre-surgical tractography aids neurosurgical planning around key language tracts. Standard reconstruction approaches lead to a trade-off between sensitivity and specificity, and may not characterise all aspects of the target tract. Goal(s): Increase sensitivity and specificity of reconstruction methods for the inferior fronto-occipital fasciculus and arcuate fasciculus and language tracts. Approach: A new set of three spherical seed, end, and supplementary waypoint regions of interest (ROIs), defined in MNI space, were implemented using volunteer datasets, and results compared to a reference atlas. Results: The new 3-ROI approach achieved greater overlap with the reference tracts (higher Dice coefficient), with increased sensitivity and/or specificity. Impact: Improvements in sensitivity and specificity of reconstructed language tracts using 3-ROI based tractography optimise the characterisation of tracts in healthy volunteers. Further evaluation should now be done to allow extension to clinical cases.