Meningiomas is a benign tumour believed to arise from arachnoid cap cells, and they usually are attached to the dura. These tumors may arise from any location where meninges exist (e.g., nasal cavity, paranasal sinuses, middle ear, mediastinum).
The incidence of meningiomas increases with age. Peak incidence is in the seventh decade in women and in the eighth decade in men.
The characteristic profile of a compressive optic neuropathy, such as that caused by Optic nerve meningioma, is usually painless, chronic progressive visual loss that may be accompanied by proptosis.
Gadolinium-enhanced fat-suppression, T1-weighted pulse sequences allow visualization of meningiomas as a localized or tubular enlargement with significant contrast enhancement.
On most MRI pulse sequences, the tumor appears isointense as compared to the optic nerve and the brain tissue. Compared to the brain tissue, meningiomas may appear hypointense on T1-weighted images and hyperintense on T2-weighted images.
Other helpful MRI techniques include enhanced fat-suppression,T1-weighted images. Intraorbital extension of intracranial meningioma can be detected easily with contrast enhanced CT scan or MRI.