Role of HRCT Temporal Bone in Pre-operative Assessment of Tegmen Height in Chronic Otitis Media Patients

Objectives: High-resolution CT (HRCT) temporal bone has emerged as a useful option in pre-operative assessment of tegmen height in chronic otitis media patients. Material and Methods: A total of 60 patients with clinical suspicion of chronic otitis media were enrolled in the study. HRCT evaluation was done using Siemens Somatom Force 384 slice multidetector computed tomography machine. We radiologically assess tegmen height using lateral semicircular canal as a reference point on HRCT. Final result has been based on correlation of radiological and intraoperative findings. Diagnostic efficacy of HRCT temporal bone was evaluated in terms of sensitivity, specificity, PPV, NPV, and accuracy for pre-operative assessment of tegmen height. Results: The correlation between actual tegmen height and estimated tegmen height (by equation) was 0.457 which is highly significant (P < 0.001). In the study, the mean tegmen height of exposed dura (ED) was 5.81 ± 1.71 (95% CI 4.91–6.70) while the mean tegmen height of non-exposed dura (NED) was 8.40 ± 1.31 (95% CI 8.02– 8.78). Highly significant difference was found in mean tegmen height between ED and NED cases (P < 0.001). Conclusion: Pre-operative CT assessment of tegmen height is an important parameter in assessing risk of dural injury during tympanomastoid surgeries.