title: Accuracy of routine fat-suppressed FLAIR and diffusion-weighted images in detecting clinically evident acute optic neuritis.
abstract: BACKGROUND
  Contrast-enhanced, fat-suppressed T1-weighted imaging (CET1WI) magnetic resonance imaging (MRI) is quite sensitive in detecting acute optic neuritis (ON), but ON remains a clinical diagnosis. MRI is indicated to evaluate demyelinating brain lesions rather than the optic nerves, while "routine" brain protocols typically include axial FLAIR and DWI.
  
  
  OBJECTIVE
  To evaluate the accuracy of axial, fat-suppressed FLAIR and DWI sequences used for our routine brain imaging in detecting acute ON, as compared to CET1WI and the clinical diagnosis.
  
  
  METHODS
  The clinical data and MRI examinations were retrospectively reviewed of 60 patients presenting to a neuro-ophthalmologist for various visual symptoms. Each patient underwent dedicated neuro-ophthalmologic examination, with axial 5 mm fat-suppressed FLAIR and DWI (part of "routine" brain MRI protocol), as well as 3 mm axial and coronal fat-suppressed CET1WI (part of dedicated orbit MRI protocol). Two neuroradiologists independently evaluated FLAIR and DWI, while CET1WI was reviewed by consensus.
  
  
  RESULTS
  Thirty-one patients were clinically positive, 29 negative for ON (total = 34 positive and 86 negative nerves). The sensitivities of FLAIR, DWI, and CET1WI for ON were 75.7-77.3%, 77.3%, and 89.5%, respectively; the specificities were 90.5-93.5%, 80.4-82.7%, and 86.0%, respectively; the accuracies were 85.7-88.2%, 79.5-81.1%, and 87.0%, respectively. Inter-observer kappa was 0.783 for FLAIR, and 0.605 for DWI; intra-observer kappa was 0.746-0.816 for FLAIR, and 0.674-0.699 for DWI (each P < 0.0001).
  
  
  CONCLUSIONS
  Being more specific, but not as sensitive, as dedicated CET1WI in acute ON, axial fat-suppressed FLAIR likely has additional value in evaluating for acute ON in "routine" brain MR protocols evaluating for demyelinating disease, while DWI may be hampered by artifacts.
authors: Department of Radiology mckinrad@umn.edu.
authors: Alexander M
authors: AM
authors: McKinney
authors: Department of Radiology.
authors: Brandon D
authors: BD
authors: Lohman
authors: Department of Radiology.
authors: Basar
authors: B
authors: Sarikaya
authors: Department of Radiology.
authors: Michael
authors: M
authors: Benson
authors: Department Ophthalmology, University of Minnesota Medical Center, Minneapolis, MN, USA.
authors: Michael S
authors: MS
authors: Lee
authors: Department of Radiology.
authors: Manferd T
authors: MT
authors: Benson
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009902:Optic Neuritis / Q000175:diagnosis*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: Head/neck; MR diffusion; MR imaging; eye; inflammation; orbit