Comparative analysis of preoperative high-resolution computed tomography temporal bone and intraoperative surgical findings in cases of cholesteatoma

Introduction: Cholesteatoma has been described as an accumulation of desquamated keratin debris in a pocket of squamous epithelium over a matrix within the middle ear cleft. A prospective study was carried out to establish a correlation between preoperative high-resolution computed tomography (HRCT) temporal bone findings with intraoperative findings in cases of cholesteatoma. Methods: Fifty patients of chronic otitis media, active squamous type, i.e. clinically suspected cholesteatoma, scheduled to undergo tympanomastoid exploration were selected. The positive and negative findings of the scan were documented as per the parameters to be analyzed. The important intraoperative surgical findings were then analyzed with preoperative HRCT findings. Results: Agreement between surgical and HRCT findings ranged from 86% (facial canal erosion) to 100% (external bony canal involvement). HRCT had higher detection rate as compared to surgery for scutum erosion (40% vs. 36%), tegmen erosion (6% vs. 4%), facial canal erosion (28% vs. 14%), lateral semicircular canal erosion (6% vs. 2%), incus erosion (78% vs. 64%), sinus tympani involvement (14% vs. 4%), attic involvement (44% vs. 42%), mastoid involvement (88% vs. 80%), and aditus widening (54% vs. 44%). The higher detection of scutum erosion, tegmen erosion, facial canal erosion, lateral semicircular canal erosion, and incus erosion is probably due to partial volume averaging. Conclusion: The findings of the present study showed that HRCT is an essential and indispensable tool for preoperative evaluation of cholesteatoma. It was highly sensitive and adequately specific for a significant number of findings. These findings are pivotal in planning the surgery and preparing for necessary anticipatory reconstructive procedures.