Fig. 11. Sarcoidosis of the optic nerves and chiasm. Bilateral insidious visual loss in a 39-year-old woman. Magnetic resonance imaging sequences (TR, 600 milliseconds; TE, 20 milliseconds). A. Coronal section shows bilateral enlargement of prechiasmal optic nerves (arrows). B. Enlarged chiasm (arrrows) in coronal section. C. Axial section. D. Midorbit section shows enlarged left optic nerve (arrow). (Courtesy of Dr. James Rush)