Computed tomography of the optic nerve: part II. Size and shape modifications in papilledema.

Increase in the caliber and course tortuosity of the optic nerve (ON) can be demonstrated by computed tomography (CT) in cases of papilledema due to intracranial tumors, hydrocephalus, pseudotumor cerebri, and other conditions causing increased intracranial pressure. The enlargement of the ON in these conditions is generally bilateral, although one of the nerves, usually of the side of the tumoral pathology, may be thicker. Enlargement on the ON may also be demonstrated by CT in papilledema due to optic neuritis. Occasionally, the thickened ON also display increased attenuation coefficient values.