CT recognition of optic nerve sheath meningioma: abnormal sheath visualization.

Abstract

Optic nerve sheath meningiomas and optic nerve gliomas can be difficult to differentiate by computed tomography (CT). Three patients with optic nerve sheath meningiomas were studied with a CT/T 8800 scanner with 1.5-mm-thick axial sections and intravenous contrast material. In each case, an abnormal optic nerve sheath was identified by CT. A soft-tissue mass arose from one side of the sheath in one patient, and the entire sheath was enlarged in two patients. This provides a basis for distinguishing optic nerve sheath meningioma from optic nerve glioma.