MRI of the optic nerve in benign intracranial hypertension.

We investigated the MRI appearance of the optic nerve and its cerebrospinal-fluid-containing sheath in 17 patients with benign intracranial hypertension (BIH) and 15 normal controls. Using phased-array local coils, 3-mm coronal T2-weighted fat-suppressed fast spin-echo images were obtained with an in-plane resolution of < 0.39 mm. The optic nerve and its sheath were clearly differentiated. An enlarged, elongated subarachnoid space around the optic nerve was demonstrated in patients with BIH. High-resolution MRI of the optic nerve offers additional information which may be of value for diagnosis and in planning and monitoring treatment.