title: Diffusion-weighted imaging in optic neuritis.
abstract: OBJECTIVE
  To evaluate imaging characteristics of optic nerves by using magnetic resonance imaging, especially diffusion-weighted imaging (DWI) with apparent diffusion coefficient measurements in acute and chronic phases of optic neuritis (ON).
  
  
  METHODS
  A retrospective study was conducted by using records of 14 patients with clinically suspected acute ON (15 nerves), 5 chronic ON (7 nerves), and 11 normal volunteers with no eye symptoms were used as controls. Magnetic resonance imaging was performed by a 1.5T scanner. Affected nerves were evaluated for sizes, signal characteristics on DWI and T2-weighted imaging (T2WI), contrast enhancement, and apparent diffusion coefficient values. Visually assessed characteristics were compared between the acute and chronic, whereas apparent diffusion coefficient values were assessed among acute ON, chronic ON, and the control groups by using the Fisher exact test and Mann-Whitney U test.
  
  
  RESULTS
  There were significant differences in the diameter of the optic nerves, hyperintensity on DWI, and enhancement characteristics on post-enhanced images in acute and chronic phases of ON (P = .0001, P < .0001, and P = .0022, respectively), apparent diffusion coefficient values of the optic nerves in acute ON, chronic ON, and control groups also differed significantly from each other.
  
  
  CONCLUSIONS
  In conclusion, DWI can add valuable information in assessment of damage to nerve and neuronal barriers and thus in predicting recovery in cases of ON.
authors.affiliation: Department of Radiology, University of Yamanashi, Yamanashi, Japan.
authors.forename: Zareen
authors.initials: Z
authors.lastname: Fatima
authors.forename: Utaroh
authors.initials: U
authors.lastname: Motosugi
authors.forename: Ali
authors.initials: A
authors.lastname: Muhi
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hori
authors.forename: Keiichi
authors.initials: K
authors.lastname: Ishigame
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Araki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002648:Child; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008297:Male; D008875:Middle Aged; D009902:Optic Neuritis / Q000175:diagnosis*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA