title: Diagnostic accuracy of screening MR imaging using unenhanced axial CISS and coronal T2WI for detection of small internal auditory canal lesions.
abstract: OBJECTIVE
  While enhanced T1WI is considered the "gold standard" for detection of internal auditory canal pathology, unenhanced fluid-sensitive sequences have shown high sensitivity for lesion identification. Our purpose was to evaluate the diagnostic accuracy of an unenhanced MR imaging protocol using axial CISS and coronal T2WI for detection of small (10 mm or less) internal auditory canal lesions.
  
  
  METHODS
  Twenty-three patients with small internal auditory canal lesions and 13 patients without lesions who had undergone MR imaging using the screening protocol and confirmatory gadolinium-enhanced thin section T1WI were identified. Two blinded neuroradiologists retrospectively evaluated all examinations using 1) only axial CISS, 2) only coronal T2WI, and 3) axial and coronal sequences together. Accuracy, specificity, sensitivity, and interobserver agreement were assessed.
  
  
  RESULTS
  Median maximum lesion dimension was 4 mm (range, 2-10 mm). Accuracy, specificity, and sensitivity for axial CISS alone were 0.94, 0.96, and 0.91 for observer 1 and 0.94, 0.92, and 1.00 for observer 2. The data for the coronal T2WI sequence only were 0.94, 0.96, and 0.91 for observer 1, and 0.99, 1.00, and 0.96 for observer 2. Using axial and coronal sequences, the data were 0.97, 0.96, and 1.00 for observer 1, and 0.99, 0.98, and 1.00 for observer 2. κ coefficients were 0.84 for the axial sequence only, 0.90 for coronal only, and 0.91 for axial and coronal both.
  
  
  CONCLUSIONS
  Screening noncontrast MR imaging using a combination of axial CISS and coronal T2WI sequences can detect small internal auditory canal lesions with 100% sensitivity and excellent interobserver agreement.
authors.affiliation: From the Departments of Radiology (T.A.A., E.P.Q., H.R.H., R.H.W.) travis.abele@hsc.utah.edu.
authors.forename: T A
authors.initials: TA
authors.lastname: Abele
authors.affiliation: Department of Radiology (D.A.B.), Naval Medical Center Portsmouth, Portsmouth, Virginia.
authors.forename: D A
authors.initials: DA
authors.lastname: Besachio
authors.affiliation: From the Departments of Radiology (T.A.A., E.P.Q., H.R.H., R.H.W.).
authors.forename: E P
authors.initials: EP
authors.lastname: Quigley
authors.affiliation: Division of Otolaryngology-Head and Neck Surgery (R.K.G., C.S., R.H.W.), University of Utah, Salt Lake City, Utah.
authors.forename: R K
authors.initials: RK
authors.lastname: Gurgel
authors.affiliation: Division of Otolaryngology-Head and Neck Surgery (R.K.G., C.S., R.H.W.), University of Utah, Salt Lake City, Utah.
authors.forename: C
authors.initials: C
authors.lastname: Shelton
authors.affiliation: From the Departments of Radiology (T.A.A., E.P.Q., H.R.H., R.H.W.).
authors.forename: H R
authors.initials: HR
authors.lastname: Harnsberger
authors.affiliation: From the Departments of Radiology (T.A.A., E.P.Q., H.R.H., R.H.W.) Biomedical Informatics (R.H.W.) Division of Otolaryngology-Head and Neck Surgery (R.K.G., C.S., R.H.W.), University of Utah, Salt Lake City, Utah.
authors.forename: R H
authors.initials: RH
authors.lastname: Wiggins
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007759:Labyrinth Diseases / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000175:diagnosis*; D015588:Observer Variation; D012189:Retrospective Studies; D012665:Semicircular Canals / Q000473:pathology*; D012680:Sensitivity and Specificity