Detection of post operative residual cholesteatoma using PROPELLER DWI combined with conventional MRI

Objective: The aim of this study is to determine the role of PROPELLER diffusion-weighted MR imaging combined with conventional MR imaging for the detection of residual cholesteatoma in patients who have undergone middle ear surgery.Subjects and methods: Twenty patients who had undergone resection of cholesteatoma were referred for MR imaging. MR imaging (1.5T) was performed using a PROPELLER DWI, T2WI, FLAIR and T1WI before and after IV injection of gadopentetate dimeglumine. An experienced reviewer evaluated the diffusion-weighted MR images for the presence of a high-signal-intensity and calculated corresponding ADC values. Imaging findings were correlated with findings from surgery in 14 patients and with findings from clinical follow-up examination in six patients.Results: Diffusion-weighted MR imaging combined with conventional MR imaging depicted eight cholesteatomas. Two lesions were missed that were <3mm. One patient was misdiagnosed as cholesteatoma, biopsy revealed acute inflammation. Sensitivity was 80%, specificity was 90%, positive predictive value was 89% and negative predictive value was 82%.Conclusion: Diffusion-weighted MR imaging combined with conventional MRI and calculation of ADC values is useful in the detection of secondary cholesteatoma and would decrease the need for un-necessary second canal wall-up operation