Biplane computed tomography of intracranial meningiomas with extracranial extension.

Fifteen of 130 intracranial meningiomas evaluated by biplane computed tomography (CT)--axial transverse and coronal--were found to have direct extracranial extension. These include five pterional meningiomas en plaque with extension to the orbit and temporal fossa; three subfrontal meningiomas invading the paranasal sinuses, nasal cavity, or orbit; three posterior fossa meningiomas with extracranial extension to the neck; three hyperostosing parasagittal meningiomas with extracranial tumors; and one tuberculum sellae meningioma with spread to the optic sheath. Biplane CT is of value in delineating the precise extent of the tumor, both intracranially and extracranially, as well as in evaluating bony changes such as hyperostosis or destruction.