title: Usefulness of delayed postcontrast magnetic resonance imaging in the detection of residual cholesteatoma after canal wall-up tympanoplasty.
abstract: OBJECTIVE
  Imaging takes an increasing place in the follow-up of patients who have undergone surgery for cholesteatoma, with computed tomography (CT) as the first line imaging technique. However, in case of complete opacity of the tympanomastoid cavities, CT is not able to differentiate residual cholesteatoma from postoperative scar tissue. The aim of this study was to assess the usefulness of magnetic resonance imaging (MRI) using delayed postcontrast T1-weighted images for the detection of residual cholesteatoma after canal wall-up tympanoplasty (CWU) in cases where CT was not conclusive.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  MRI, with delayed postcontrast T1-weighted images (30-45 minutes after contrast injection), was performed before revision surgery in 41 consecutive patients who had undergone CWU for cholesteatoma and presenting with a nonspecific complete opacity of the mastoid bowl on CT. In all the cases, imaging results were compared with operative findings at surgical revision.
  
  
  RESULTS
  A residual cholesteatoma was found in 19 of 41 patients at revision surgery and was correctly detected on MRI in 17 patients. In the two remaining cases, cholesteatoma pearls smaller than 3 mm were not seen. There was no false-positive case. Statistics were as follows: sensitivity 90%; specificity 100%; positive predictive value 100%; negative predictive value 92%.
  
  
  CONCLUSIONS
  When postoperative CT is not conclusive because of complete opacity of the tympanomastoid cavities, MRI with delayed postcontrast T1-weighted images is a reliable additional technique for the detection of a residual cholesteatoma when its diameter is at least 3 mm.
authors.affiliation: ENT Department, Fondation Rothschild, Paris, France. dayache@fo-rothschild.fr
authors.forename: D
authors.initials: D
authors.lastname: Ayache
authors.forename: M T
authors.initials: MT
authors.lastname: Williams
authors.forename: D
authors.initials: D
authors.lastname: Lejeune
authors.forename: A
authors.initials: A
authors.lastname: Corré
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D018424:Cholesteatoma, Middle Ear / Q000175:diagnosis* / Q000601:surgery; D002921:Cicatrix / Q000175:diagnosis; D003287:Contrast Media; D005260:Female; D005355:Fibrosis; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008416:Mastoid / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D011182:Postoperative Care; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012086:Reoperation; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014433:Tympanoplasty / Q000379:methods*
chemical_list: D003287:Contrast Media