Learning Objectives:

Introduction: Magnetic resonance imaging (MRI) is becoming increasingly used as a tool for cholesteatoma diagnosis. The purpose of this retrospective study was to assess a role of T1 weighted imaging (T1WI) in diagnosing recurrent temporal bone cholesteatoma with Diffusion-weighted MR imaging (DWI).

Method: We studied 44 patients (45 temporal bones) with preoperatively suspected cholesteatoma. Each patient underwent an MRI examination including both DWI and T1WI. Diagnosis of cholesteatoma was based on the evidence of a high intense image on DWI. Results of MRI were compared with operative diagnosis.

Result: The patients were consisted of 24 males and 20 females, ranging in age between 8 and 87 (median age = 53). DWI accurately predicted the presence of cholesteatoma in 31 of 36 cases, and it correctly excluded in 5 of 9 cases. False positives included 2 cholesterol granulomas, 1 schwannoma, and 1 fibrosis. False negatives included 4 small keratin pearls, 1 wetter debris caused by infections. Overall sensitivity and specificity for detection of cholesteatoma were 86.1% and 55.6%, respectively. Positive predictive value and negative predictive value were 88.6% and 50.0%, respectively. Overall accuracy for detection of cholesteatoma was 80.0%.Only 5.6% of cholesteatomas (2/36) showed high intensity on T1WI, on the other hand, 75.0% of false positives (3/4) showed high intensity on T1WI. When diagnosis of cholesteatoma was based on the evidence of both high intensity on DWI and low or intermediate intensity on T1WI, overall accuracy for detection of cholesteatoma increased to 82.2%.

Conclusion: The combination of DWI and T1WI may improve specificity and overall accuracy for detection of cholesteatoma.