title: Evaluation of cholesteatoma: our experience with DW Propeller imaging.
abstract: BACKGROUND
  Cholesteatoma management includes early detection and surgical exploration. Due to its tendency to recur, it can be potentially locally aggressive. Magnetic resonance imaging (MRI), and in particular diffusion weighted imaging (DWI), plays an important role in management of these lesions.
  
  
  OBJECTIVE
  To assess the accuracy of Propeller (Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction) DW sequence in detecting middle ear and mastoid cholesteatomas in non-operated ears by surgical correlation.
  
  
  METHODS
  A retrospective review of 15 patients was done who underwent Propeller DWI with either clinically confirmed or suspected cholesteatomas. Surgical correlation was done in all cases.
  
  
  RESULTS
  All patients had hyperintense foci on Propeller DWI. Surgical correlation performed revealed that 13 patients had cholesteatomas while two patients had mastoid abscesses. The location, extent, and size of cholesteatomas on Propeller DWI matched with the operative findings. Of the 13 patients with cholesteatomas, three patients had multiple foci of hyperintensity on Propeller DWI, which corroborated with the surgical finding of multiple cholesteatomas. The average apparent diffusion coefficient value of cholesteatoma was 0.868 × 10(-3) mm(2)/s, found to be higher than that of abscess, which was 0.425 × 10(-3) mm(2)/s.
  
  
  CONCLUSIONS
  Propeller DWI was accurate in assessing the location, extent, and size of cholesteatomas as corroborated with surgical findings. Propeller DWI is useful in detecting number of cholesteatoma foci, a vital finding as it may impact the choice of surgery.
authors.affiliation: Department of Radiology, Tan Tock Seng Hospital, Singapore amit_karandikar@ttsh.com.sg.
authors.forename: Amit
authors.initials: A
authors.lastname: Karandikar
authors.affiliation: Department of Radiology, Tan Tock Seng Hospital, Singapore.
authors.forename: Siu Cheng
authors.initials: SC
authors.lastname: Loke
authors.affiliation: Department of Radiology, Tan Tock Seng Hospital, Singapore.
authors.forename: Julian
authors.initials: J
authors.lastname: Goh
authors.affiliation: Department of Otorhinolaryngology, Tan Tock Seng Hospital, Singapore.
authors.forename: Seng Beng
authors.initials: SB
authors.lastname: Yeo
authors.affiliation: Department of Radiology, Changi General Hospital, Singapore.
authors.forename: Tiong Yong
authors.initials: TY
authors.lastname: Tan
mesh_terms: D018424:Cholesteatoma, Middle Ear / Q000175:diagnosis* / Q000601:surgery; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D012189:Retrospective Studies
keywords: Propeller DWI; abscess; cholesteatoma; hyperintensity; multiple; non-echo planar