title: Labyrinthitis ossificans: how accurate is MRI in predicting cochlear obstruction?
abstract: OBJECTIVE
  To determine the accuracy of preoperative MRI in predicting cochlear obstruction in pediatric patients with a history of bacterial meningitis.
  
  
  METHODS
  A case series with chart review was performed at a tertiary care multidisciplinary cochlear implant program. Forty-five children with hearing loss that resulted from bacterial meningitis were implanted from 1991 to 2006. Twenty-five children had preoperative MRI with high-resolution axial T2-weighted images to assess for cochlear patency.
  
  
  RESULTS
  Seventeen of 25 patients (68%) had surgical evidence of cochlear obstruction. Six patients (37.5%) required circummodiolar drill-outs, and one patient (6.25%) underwent placement of a double array cochlear implant. The nine remaining patients (56%) with cochlear obstruction required removal of fibrous tissue or drilling of the inferior basal turn, but did not require manipulation of the ascending basal turn to achieve full electrode insertion. The sensitivity, specificity, and positive and negative predictive value of MRI predicting intraoperative cochlear obstruction with 95 percent confidence intervals was 94.1 percent (71-99), 87.5 percent (47-99), 94.1 percent (71-99) and 87.5 percent (47-99), respectively.
  
  
  CONCLUSIONS
  Preoperative high-resolution T2 MRI may be useful in predicting cochlear obstruction in patients with a prior history of bacterial meningitis.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA. brandon.isaacson@utsouthwestern.edu
authors.forename: Brandon
authors.initials: B
authors.lastname: Isaacson
authors.forename: Timothy
authors.initials: T
authors.lastname: Booth
authors.forename: Joe W
authors.initials: JW
authors.lastname: Kutz
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Lee
authors.forename: Peter S
authors.initials: PS
authors.lastname: Roland
mesh_terms: D002648:Child; D003051:Cochlea / Q000473:pathology*; D019929:Cochlear Implantation; D003054:Cochlear Implants; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000209:etiology / Q000601:surgery*; D006801:Humans; D007762:Labyrinthitis / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D016920:Meningitis, Bacterial / Q000150:complications*; D009999:Ossification, Heterotopic / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011300:Preoperative Care; D012680:Sensitivity and Specificity