文摘
A 45-year-old man suffered sudden visual loss with Marcus-Gunn pupil anda central scotoma in the right eye as evaluated by visual field examination.The patient's right visual acuity was 0.02 (0.08× - 4.5D).T1-weighted magnetic resonance imaging (MRI) demonstrated a cystic lesion ofhigh intensity in the right sphenoid sinus. Short TI inversion recovery(STIR) images presented a cystic lesion of high intensity in the rightsphenoid sinus. In addition, a ring-shaped high intensity signal was seensurrounding the right optic nerve. Post-contrast fat suppression T1-weightedimages did not demonstrate any enhancement within the right optic nerve.After intranasal sphenoidectomy, good recovery of the right visual acuitywas noted. On subsequent MRI, the cystic lesion in the sphenoid sinusdisappeared. Also, the ring of high intensity surrounding the right opticnerve became unclear. It was thought that the ring of hyperintentisy seen onthe STIR images demonstrated cerebrospinal fluid in the dilated periopticsubarachnoid space. Therefore, these MRI findings suggested that the acutevisual loss resulted from a disturbed blood supply to the optic nerve due tocompression by the sphenoidal mucocele, and not due to an inflammatoryprocess.