The probabilistic (n = 12) atlas label in MNI space of the isRt is shown (red-to-yellow) with neighboring nuclei (white arrows), such as PTg (green), CnF (blue), entire mRt (cool), and MiTg-PBG (red). As a background image, we used the FA map in the MNI space. Very good (i.e., up to 100%) spatial agreement of labels across subjects was observed, indicating the feasibility of delineating the probabilistic labels of these nuclei. CnF, cuneiform nucleus; MiTg-PBG, microcellular tegmental nucleus–prabigeminal nucleus; PTg, pedunculotegmental nucleus.