Abstract: Methods, systems, and apparatus for brain tractography by shading fiber bundles. In one aspect, a method includes forwarding patient brain data for presentation to a user; receiving, from the user, a selection of a brain parcel in response to presentation of the patient brain data; forwarding, for display to the user, tract health data comprising i) tract data for tracts connected to the brain parcel and ii) at least one metric for the tracts, the metric reflecting the health of the tracts; and taking an action in response to forwarding the tract health data.