Figure2. Assessment of tumor extension. an expansile mass of right sphenoid sinus , eroding the bone laterally and superiorly, pressing against the optic nerve . The mass encase internal carotid artery, but does not cause stenosis (A and B) with homogenous enhancement (C and D).A and B: Axial T1W and T2W MR image; and C and D: sagital and coronal gadolinium-enhanced T1W MR images.