title: Orbital and optic pathway sarcoidosis: MR findings.
abstract: OBJECTIVE
  To identify and characterize the MR findings of sarcoidosis when it involves the orbit and visual pathways.
  
  
  METHODS
  The MR scans of 15 patients, 3 with presumed and 12 with proved orbital or optic pathway sarcoidosis were retrospectively reviewed.
  
  
  RESULTS
  Eight patients had MR evidence of optic nerve involvement by sarcoid granuloma. Perineural enhancement was seen in four cases, optic atrophy in one. Three who had had unenhanced scans showed optic nerve enlargement. Nine patients had optic chiasmal involvement. One patient had increased T2 signal in the optic radiations. Three patients had orbital masses that had MR signal characteristics similar to pseudotumor. Five patients had periventricular white matter abnormalities closely resembling multiple sclerosis.
  
  
  CONCLUSIONS
  Sarcoidosis should be considered in the differential diagnosis of optic nerve or nerve sheath enhancement on MR. Orbital sarcoidosis has MR characteristics very similar to pseudotumor.
authors.affiliation: University of Arizona Medical Center, Tucson 85724.
authors.forename: R F
authors.initials: RF
authors.lastname: Carmody
authors.forename: M F
authors.initials: MF
authors.lastname: Mafee
authors.forename: J A
authors.initials: JA
authors.lastname: Goodwin
authors.forename: K
authors.initials: K
authors.lastname: Small
authors.forename: C
authors.initials: C
authors.lastname: Haery
mesh_terms: D000293:Adolescent; D000328:Adult; D002426:Cavernous Sinus / Q000473:pathology; D003287:Contrast Media; D004338:Drug Combinations; D005260:Female; D005682:Gadolinium; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement; D007766:Lacrimal Apparatus Diseases / Q000175:diagnosis; D008279:Magnetic Resonance Imaging; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D009886:Ophthalmoplegia / Q000175:diagnosis; D009896:Optic Atrophy / Q000175:diagnosis; D009897:Optic Chiasm / Q000473:pathology; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D009916:Orbital Diseases / Q000175:diagnosis*; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives; D012189:Retrospective Studies; D012507:Sarcoidosis / Q000175:diagnosis*
chemical_list: D003287:Contrast Media; D004338:Drug Combinations; D009942:Organometallic Compounds; D008536:Meglumine; D004369:Pentetic Acid; D005682:Gadolinium; D019786:Gadolinium DTPA