Role of diffusion-weighted MRI in the detection of cholesteatoma after tympanoplasty

IntroductionConventional cross sectional imaging modalities are unable to differentiate cholesteatoma from post surgery alterations in a surgical cavity.ObjectiveThe aim of this prospective study was to determine the value of diffusion-weighted (DW) MRI for the detection of cholesteatoma in patients who have undergone middle ear surgery.Study designA prospective comparative study.Main outcome measureThe presence of cholesteatoma at revision surgery and matched with the preoperative findings of MRI.Subjects and methodsTwenty-one ears previously operated for cholesteatoma and scheduled for surgery were referred for MRI using a DW fast spin-echo sequence, T2-weighted spin-echo sequence and T1-weighted before and after contrast injection as well as delayed contrast-enhanced images. Imaging findings were correlated with intraoperative findings.ResultsDW MRI combined with conventional MRI accurately depicted 11 of 13 cholesteatoma patients (sensitivity = 84.6%). The two lesions that were missed were 2 mm in size. All the MRI of patients without cholesteatoma were correctly interpreted as showing negative findings for cholesteatoma (specificity = 100%). The positive predictive value and negative predictive value were 100% and 80%, respectively.ConclusionDW MRI combined with conventional MRI show high signal intensity in the presence of residual or recurrent cholesteatoma and could correctly detect its presence in the surgical cavity. However, small lesions can be missed.