title: Prognostic value of extension patterns on follow-up magnetic resonance imaging in patients with necrotizing otitis externa.
abstract: OBJECTIVE
  To analyze the clinical characteristics of necrotizing otitis externa (NOE) and to evaluate the prognosis according to the progression of disease in terms of extension patterns on follow-up magnetic resonance images.
  
  
  METHODS
  A retrospective clinical study.
  
  
  METHODS
  Tertiary academic center.
  
  
  METHODS
  We reviewed medical records of 36 patients with NOE followed up by temporal bone magnetic resonance images on a regular basis from January 1, 1992, through December 31, 2008.
  
  
  METHODS
  The initial compartments affected by NOE were defined as 4 categories: anterior, medial, midline, and intracranial and extracranial. The extensions of NOE were evaluated by comparison between initial and follow-up magnetic resonance images 6 months later and defined by the direction of spread from one to another compartment and/or disease progression within the same compartment. The patients were divided into 3 groups (limited, single, and multiple extension groups) on the basis of the multiplicity of extension routes. The clinical characteristics and prognostic factors were investigated, and overall survival rates were compared according to extension patterns.
  
  
  RESULTS
  Retrocondylar fat infiltration (86%) was the most common finding, followed by parapharyngeal fat infiltration (81%) and ipsilateral nasopharyngeal musculature thickening (75%). Anterior and medial extension patterns were observed in 3 (8%) and 5 (14%) patients, respectively. Eighteen patients (50%) with combined extension patterns showed a significantly lower overall survival rate than those with single and limited extension patterns (P = .01).
  
  
  CONCLUSIONS
  The retrocondylar fat infiltration was the earliest change in NOE, and combined extension patterns may be a poor prognostic factor in patients with NOE.
authors.affiliation: Department of Otorhinolaryngology, Seoul National University College of Medicine, 101 Daehagno, Jongno-Gu, Seoul, Korea.
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Lee
authors.forename: Jae-Jin
authors.initials: JJ
authors.lastname: Song
authors.forename: Seung-Ha
authors.initials: SH
authors.lastname: Oh
authors.forename: Sun O
authors.initials: SO
authors.lastname: Chang
authors.forename: Chang-Hee
authors.initials: CH
authors.lastname: Kim
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D004388:Dura Mater / Q000473:pathology; D004431:Ear, External / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007262:Infusions, Intravenous; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D010032:Otitis Externa / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D013506:Otologic Surgical Procedures / Q000379:methods; D011379:Prognosis; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents