Preoperative diffusion-weighted magnetic resonance imaging for detection of middle ear cholesteatoma

Recently an increasing number of studies concerning of usefulness of preoperative diffusion-weighted magnetic resonance imaging for detection of primary or recurrent cholesteatoma have been reported. In order to assess the usefulness of diffusion-weighted imaging (DWI), we conducted the pre-operative periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) -DWI using 1.5T or 3TMR units for 63 patients with chronic otitis media. Patients suspected of having or requiring re-operation of middle ear cholesteatoma who underwent preoperative MRI and CT for cholesteatoma surgery between March 2011 and September 2012 were investigated. <br>There were 34 males and 29 females, with an average age of 48 (range: 6-88) years. 39 cases were receiving their first surgery and the remaining 24 cases were postoperative. <br>Final diagnosis was surgically confirmed. <br>We assessed the sensitivity, specificity, and positive and negative predictive value of preoperative DWI and CT for detecting cholesteatoma. <br>Overall (n=63), the sensitivity, specificity, and positive and negative predictive value of DWI were 95.3%, 75%, 89.1% and 88.2%, those of CT 90.6%, 70%, 86.7% and 77.8% respectively. <br>In the 39 cases receiving their first surgery, the sensitivity, specificity, and positive and negative predictive value of DWI were 93.9%, 50%, 91.1% and 60% and those of CT 96.9%, 33.3%, 88.8% and 66.6% respectively. In the 24 postoperative cases, the sensitivity, specificity, and positive and negative predictive value of DWI were 100%, 85.7%, 83.3% and 100%, and those of CT 70%, 85.7%, 77.7% and 80% respectively. <br>One of these cases was negative by preoperative diagnosis (DWI) but positive by preoperative CT. A cholesteatoma was confirmed by surgery but it was found to be desiccated. <br>Both CT and MRI showed high sensitivity for preoperative evaluation of chronic otitis media with cholesteatoma. <br>The drawback of DWI is that a false-negative result can be obtained if a cholesteatoma is present but desiccated. <br>If CT findings provide information about invasion to mastoid cells or the auditory ossicles, the possibility of chronic otitis media with cholesteatoma should be considered even if DWI is negative. DWI was thought to be an useful reference for follow-up of postoperative cases with cholesteatoma in which bone shapes showed deformities.