title: Pre-operative high resolution computed tomography scans for cholesteatoma: has anything changed?
abstract: OBJECTIVE
  CT temporal bone scans are often performed to aid in surgical planning and management of cholesteatomas. With improvements in the resolution of CT scans today, it is now possible to obtain more information from these scans than before. The aim of this study is to compare findings on high resolution CT (HRCT) temporal bone scans to intra-operative findings, so as to determine how well various middle ear structures are assessed by HRCT scanning.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Otology clinic of a tertiary otolaryngology centre.
  
  
  METHODS
  32 mastoidectomies performed by a single otologist for clinically confirmed cholesteatoma were included. Correlation of CT and intra-operative findings on the status of structures including the ossicles, semicircular canals, facial canal and tegmen was analysed using kappa and AC1 statistics.
  
  
  RESULTS
  In all patients, a soft tissue mass with bony erosion in keeping with a cholesteatoma was seen on CT. Radiosurgical agreement was excellent for the presence of semicircular canal erosion (k=0.89, AC1=0.96), facial canal dehiscence (k=0.74, AC1=0.76), tegmen erosion (k=0.76, AC1=0.92) and malleus erosion (k=0.76, AC1=0.85). It was good for incus erosion (k=0.71, AC1=0.92) and stapes erosion (k=0.63, AC1=0.73).
  
  
  CONCLUSIONS
  There was good to excellent radiosurgical agreement in the assessment of the status of various middle ear structures. Improvement in radiosurgical agreement from existing studies in the literature was noted. This was especially true for features such as facial canal dehiscence. With technological advancements, CT temporal bone scans appear even more valuable for evaluation of patients prior to cholesteatoma surgery.
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Changi General Hospital.
authors.forename: Jia Hui
authors.initials: JH
authors.lastname: Ng
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Changi General Hospital.
authors.forename: Edward Zhiyong
authors.initials: EZ
authors.lastname: Zhang
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Changi General Hospital.
authors.forename: Sue Rene
authors.initials: SR
authors.lastname: Soon
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Changi General Hospital.
authors.forename: Vanessa Yee Jueen
authors.initials: VY
authors.lastname: Tan
authors.affiliation: Department of Radiology, Changi General Hospital.
authors.forename: Tiong Yong
authors.initials: TY
authors.lastname: Tan
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Khoo Teck Puat Hospital.
authors.forename: Paul Kan Hwei
authors.initials: PK
authors.lastname: Mok
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Changi General Hospital; Department of Otolaryngology-Head & Neck Surgery, Khoo Teck Puat Hospital. Electronic address: heng_wai_yuen@cgh.com.sg.
authors.forename: Heng Wai
authors.initials: HW
authors.lastname: Yuen
mesh_terms: D000328:Adult; D018424:Cholesteatoma, Middle Ear / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D013506:Otologic Surgical Procedures; D011300:Preoperative Care / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013701:Temporal Bone / Q000000981:diagnostic imaging* / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000379:methods*