Differentiation between cholesteatoma and inflammatory process of the middle ear, based on contrast-enhanced computed tomography imaging.

OBJECTIVE To assess the usefulness of delayed post-contrast computed tomography (CT) examination for the detection of residual or recurrent cholesteatoma after canal wall up tympanoplasty. STUDY DESIGN AND SETTING This prospective, non-randomized study, set within an academic medical centre, included 17 consecutive patients who had undergone canal wall up tympanoplasty for cholesteatoma, with possible recurrence. Pre-contrast CT scans and delayed post-contrast images were compared with second look surgical findings. RESULTS A residual or recurrent cholesteatoma was found in eight of the 17 patients at revision surgery and was correctly diagnosed on post-contrast CT images in six patients (75 per cent). In the two misdiagnosed cases, cholesteatoma pearls smaller than 2.5 mm were not seen on post-contrast CT. The sensitivity of the imaging test was 75 per cent, the specificity was 60.1 per cent, the positive predictive value was 88.1 per cent and the negative predictive value was 81.8 per cent. CONCLUSION Computed tomography with delayed post-contrast images is a sensitive imaging modality for the detection of residual cholesteatoma. If proven reliable, this method of non-invasive imaging could spare the patient unnecessary revision surgery.