Swelling of the retrobulbar intra-orbital segment of the left optic nerve, extending to the intracranial segment without involvement of optic chiasm. The swollen left optic nerve has signal intensity on T2WI well-visualized on coronal T2 fat suppressed sequence and shows enhancement on postcontrast T1 fat suppressed sequence.
Indistinct margin of the intra-orbital segment of left optic nerve to the surrounding subarachnoid space within the optic sheath.
The right optic nerve is normal in size. No abnormal signal intensity or enhancement.