Magnetic resonance imaging of the orbit.

Magnetic resonance (MR) imaging plays an important role in evaluation of ocular and orbital lesions. Ocular tumors can be distinguished and delineated from adjacent fluid collections. Demonstration of internal septa within a well-defined mass leads to the diagnosis of cavernous hemangioma, whereas vascularity and internal lobulations are the hallmark of capillary hemangiomas. MR is the procedure of choice for evaluation of the optic nerve sheath complex. It precisely delineates and characterizes optic neuritis, optic gliomas, and perioptic meningiomas.