Anatomic relationship of the oculomotor nuclear complex and medial longitudinal fasciculus in the midbrain.

PURPOSE To compare the MR characteristics of the oculomotor nucleus with its appearance on anatomic images. METHODS Specimens of cadaveric brains were imaged in a 3.0-T MR imager equipped with a 3.0-cm solenoid coil. The specimens were sectioned, stained, and examined histologically. On anatomic sections, the oculomotor nuclei, medial longitudinal fasciculus, red nuclei, and oculomotor nerve were identified. The MR images were then compared with the anatomic sections. RESULTS The oculomotor nuclei, medial longitudinal fasciculus, red nuclei, and oculomotor nerve could be identified on MR images by their size, shape, signal intensity, and location. CONCLUSION MR images show the anatomic relationship of the oculomotor nerve complex, medial longitudinal fasciculus, and related structures in the brain stem.