Role of Diffusion-weighted Magnetic Resonance Imaging in Differentiating Cholesteatoma from Chronic Suppurative Otitis Media: A Cross-sectional Study

Abstract

Introduction: Radiological imaging, such as High-resolution Computed Tomography (HRCT) of the temporal bone, has always held significant importance in diagnosing and staging Chronic Suppurative Otitis Media (CSOM). In preoperative cases of CSOM and cholesteatoma, HRCT describes the disease’s extent to aid in surgical approach, while diffusion-weighted Magnetic Resonance Imaging (MRI) sequences can differentiate cholesteatoma from other common inflammatory middle ear diseases. Aim: To determine the role of Diffusion-weighted Magnetic Resonance Imaging (DW-MRI) in differentiating between granulation tissue and cholesteatoma using histopathological findings as a reference standard. Materials and Methods: A hospital-based cross-sectional study was conducted in the Department of Radiodiagnosis, Sri Manakula Vinayagar Medical College, Puducherry, India, from November 2018 to April 2020. A total of 40 patients who underwent HRCT of the temporal bone for preoperative evaluation of CSOM underwent diffusion sequence MRI, and their findings were compared with intraoperative and postoperative histopathological results. Findings such as soft-tissue masses with scutum and erosion of ear ossicles were analysed in HRCT, while diffusion restriction was observed in DW-MRI in cases of cholesteatoma. Data were collected using a prescribed proforma and analysed using Statistical Package for Social Sciences (SPSS) software version 24.0. Results: The mean±Standard Deviation (SD) age of the patients was 43±20.41 years (27 males, 13 females). The most common presentations in this study were mucopurulent discharge and conductive hearing loss (20 out of 40 patients). Among the 16 patients diagnosed with cholesteatoma through histopathological examination, all (100%) were reported to have diffusion restriction present in the MRI. The sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) of DWI were all found to be 100% in diagnosing cholesteatoma. The sensitivity of HRCT was 81.25% and the specificity was 83.3%. Conclusion: High-resolution computed tomography provides a surgical roadmap indicating the extent of involvement and bony structures, while DW-MRI imaging helps in differentiating cholesteatoma from CSOM. A combined preoperative approach using HRCT and DW-MRI imaging can aid in diagnosing cholesteatoma effectively.

Keywords

• ossicular erosion
• restricted diffusion
• scutum erosion