title: The signal intensity ratio of the optic nerve to ipsilateral frontal white matter is of value in the diagnosis of acute optic neuritis.
abstract: OBJECTIVE
  To evaluate the usefulness of the signal intensity ratio (SIR) of the optic nerve to the white matter (WM) on short tau inversion recovery (STIR) images to diagnose acute optic neuritis (AON).
  
  
  METHODS
  The 405 consecutive patients with suspected orbital diseases underwent orbital magnetic resonance imaging (MRI) using a 3-T scanner between June 2008 and August 2011. Among them, 108 optic nerves (33 AON and 75 control) were retrospectively analysed. The averaged SIR (SIRave) and maximum SIR (SIRmax) were defined as the averaged signal intensity (SI) of the optic nerve divided by that of WM, and the maximum SI of the optic nerve divided by averaged SI of WM, respectively. These values were compared between AON and control using the Mann-Whitney U test. A P < 0.05 was considered statistically significant.
  
  
  RESULTS
  SIRave and SIRmax were significantly (P < 0.001) higher in the AON compared to the control. At a cut-off SIRave value of 1.119, the sensitivity, specificity and accuracy were 0.939, 0.840, and 0.870; and at a cut-off SIRmax value of 1.281, these were 1.000, 0.720 and 0.806, respectively.
  
  
  CONCLUSIONS
  The SIR of the optic nerve to WM on STIR images is of value in diagnosing AON.
  
  
  CONCLUSIONS
  • We propose a method of diagnosing acute optic neuritis using 3-T MRI. • Our method is simple and objective and requires no novel imaging techniques. • Our method shows high diagnostic accuracy.
authors.affiliation: Department of Diagnostic Radiology, School of Medicine, Sapporo Medical University, South 1 West 17, Chuo-Ku, Sapporo City, 060-8556, Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Onodera
authors.affiliation: Department of Diagnostic Radiology, School of Medicine, Sapporo Medical University, South 1 West 17, Chuo-Ku, Sapporo City, 060-8556, Japan. nyama@sapmed.ac.jp.
authors.forename: Naoya
authors.initials: N
authors.lastname: Yama
authors.affiliation: Department of Ophthalmology, School of Medicine, Sapporo Medical University, Sapporo, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Hashimoto
authors.affiliation: Department of Diagnostic Radiology, School of Medicine, Sapporo Medical University, South 1 West 17, Chuo-Ku, Sapporo City, 060-8556, Japan.
authors.forename: Takaharu
authors.initials: T
authors.lastname: Shonai
authors.affiliation: Department of Diagnostic Radiology, School of Medicine, Sapporo Medical University, South 1 West 17, Chuo-Ku, Sapporo City, 060-8556, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Aratani
authors.affiliation: Division of Radiology and Nuclear Medicine, Sapporo Medical University Hospital, Sapporo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takashima
authors.affiliation: Liberal Arts and Sciences, Center for Medical Education, Sapporo Medical University, Sapporo, Japan.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Kamo
authors.affiliation: Division of Radiology and Nuclear Medicine, Sapporo Medical University Hospital, Sapporo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nagahama
authors.affiliation: Department of Ophthalmology, School of Medicine, Sapporo Medical University, Sapporo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohguro
authors.affiliation: Department of Diagnostic Radiology, School of Medicine, Sapporo Medical University, South 1 West 17, Chuo-Ku, Sapporo City, 060-8556, Japan.
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Hatakenaka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009900:Optic Nerve / Q000000981:diagnostic imaging*; D009902:Optic Neuritis / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D066127:White Matter / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: Diagnosis; Magnetic resonance imaging; Optic neuritis; Quantitative evaluation; Retrospective study