Role of Diffusion-Weighted Magnetic Resonance Imaging in the Evaluation of Clinically Suspected Cholesteatoma Cases.

Abstract

To analyze the apparent diffusion coefficient (ADC) values of middle ear and mastoid lesions in Diffusion weighted Magnetic Resonance Imaging (DW-MRI) to arrive at a probable demarcating value to differentiate cholesteatoma from non-cholesteatomatous lesions. Accurate anatomic localization of the lesion was also done using High Resolution Computed Tomography (HRCT) temporal bone. The study cohort consisted of 30 patients who had undergone HRCT, DW-MRI and surgical intervention in clinically suspected cholesteatomatous lesions during the period August 2018 to August 2020.Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy values of HRCT and MRI in relation to intraoperative findings and histopathological findings (gold standard) were calculated and compared using the 2-sided McNemar's Chi Square test. Receiver operating characteristic (ROC) curve was used to predict the cut off value of ADC to differentiate between cholesteatoma and non cholesteatomatous lesions. Total patients were 30 out of which 15 were histopathologically proven cholesteatoma. MR DWI showed 100% sensitivity, 80% specificity, and 90% accuracy in diagnosing cholesteatoma compared to HPE. The probable cut off value of ADC in differentiating cholesteatoma from non-cholesteatomatous lesions was found to be < 1.226 × 10-3 mm2/s, statistically using ROC curve. HRCT showed 96.6% accuracy in identifying the location of the lesion. MR-DWI is a useful tool both individually and in combination with HRCT in the diagnosis of cholesteatomas with high accuracy. An ADC cut-off value could also significantly help increase the accuracy of diagnosis.