Mesencephalic anatomy: demonstration by computed tomography.

Although gray and white matter are distinguished by computed tomography (CT) in the cerebrum and cerebellum, their resolution in the mesencephalon has not been reported. CT and anatomic sections of the mesencephalon were compared to determine the relative densities of the superior cerebellar peduncles (white matter) and red nuclei and central gray matter. The normal low attenuation of the superior cerebellar peduncle should not be misinterpreted as infarction or demyelination.