Diffusion Weighted MRI Accuracy in Cholesteatoma Localization

inclusion criteria * Age: from 1 month and up * Sex: man / woman * Patient who had a tympanoplasty in closed technique, for the first surgical time of a cholesteatoma or for residual or recurrent cholesteatoma, performed by the same radiologist (Pr Anne Charpiot) with the following characteristics: * Code of the Common Classification of Medical Acts (CCAM) * Exeresis of cholesteatoma with tympanoplasty in closed technique and ossiculoplasty (CBFA002) * Exeresis of cholesteatoma with tympanoplasty in closed technique (CBFA006) * Exeresis of cholesteatoma confined to the tympanic cavity without antro-attic exploration (CBFA005) * Tympanoplasty in closed technique with posterior tympanotomy (CBMD001) * Secondary tympanoplasty in closed technique (CBMD002) * Diagnostic code of the International Classification of Diseases (ICD10) * Cholesteatoma of the middle ear (H71) * Diagnosis of macroscopic and / or pathological cholesteatoma. * Preoperative diagnosis of cholesteatoma on MRI of the middle ear performed in less than 6 months by the same radiologist (Pr Francis Veillon). * Subject (or the holders of parental authority in the case of minors) having agreed to the use of medical data for the purpose of this research. Cholesteatoma is a very common disease in the pediatric population, with important functional issues, whose treatment is surgical. That's why our study includes minor subjects. Criteria of non-inclusion * Refusal of the patient to participate in the study * Absence of data concerning the diagnosis and / or localization of cholesteatoma on the operative record * Subject under the protection of justice * Subject under guardianship or curatorship * Pregnancy (woman of childbearing age) * Breastfeeding