Location of the corticospinal tract within the brainstem

Axial images through brainstem with diffusion-tensor imaging demonstrate the position of right corticospinal tract (CST) at level of upper midbrain (A), lower midbrain (B), upper pons (C), and mid-pons (D). On color-encoded maps, blue indicates tracts coursing cranial-to-caudal, red indicates tracts coursing in transverse direction, and green indicates tracts coursing in anterior-to-posterior direction.