These images contain probability maps for 20 major white matter tracts, based on the Johns Hopkins template (Hua K, Zhang J, Wakana S, Jiang H, Li X, et al. (2008) Tract probability maps in stereotaxic spaces: analyses of white matter anatomy and tract-specific quantification. Neuroimage 39: 336–347). The template used is the one that is provided together with the FSL software (and downloaded from: https://github.com/vistalab/vistasoft/blob/master/mrDiffusion/templates/MNI_JHU_tracts_prob.nii.gz). The atlas was resampled to the standard MNI T2-weighted template, and each volume was extracted into a separate file based on https://github.com/vistalab/vistasoft/blob/master/mrDiffusion/templates/MNI_JHU_tracts_prob.txt. The code for this transformation is provided in a Jupyter notebook.