Correlation of preoperative hrct temporal bone with intraoperative findings in unsafe csom:- statistical analysis

Background: HRCT is often used to evaluate diseases of middle ear and mastoid such as cholesteatoma and gives useful information to the surgeon about the possible anatomical variations and extent of underlying disease process and thus complements the clinical examination. This study was undertaken to compare the Preoperative HRCT and intra-operative findings in unsafe CSOM. Material and Methods: This prospective study was conducted in the Department of ENT HNS in a tertiary care hospital on a sample size of 55 patients with clinical diagnosis of unsafe CSOM. HRCT temporal bone was done in all enrolled patients who were subsequently operated. The intra-operative findings were compared with preoperative HRCT and results were analysed using standard statistical methods. Results: Majority of patients were in the age group of 21-30 years with a total of 31 (56.36%) male and 24(43.64%) female patients. The study showed bony erosion in 48(87.27%) patients on HRCT that included erosion of scutum, tegmen, sigmoid Sinus plate, external auditory canal, Facial nerve canal, lateral semicircular canal and erosion of Malleus, Incus and stapes in 37(67.27%) patients,7(12.72%) patients, 3(5.45%) patients, 7(12.72%) patients, 5(9.09%) patients,3(5.45%) patients,20(36.36%) patients, 31(56.36%) patients and 24(43.63%) patients and the results for the same findings intra-operatively were 36 (65.45%) patients, 8(14.54%) patients,5(9.09%) patients, 8(14.45%) patients 7(12.72%) patients,2(3.63%) patients, 24(43.63%) patients, 34(61.81%) patients and 26(47.27%) patients respectively. In the detection of bony erosion HRCT showed an average sensitivity of 85.96%, specificity of 99.91%,PPV of 94.43%,NPV of 93.36% and an average accuracy of 96.52% and results for the detection of soft tissue lesions depicting cholesteatoma showed an average sensitivity of 98.20%,specificity of 96.88%,PPV of 89.42%,NPV of 96.75% and an average accuracy of 97.75%.Conclusion:HRCT serves as a road map to assist the surgeon in planning the management and predict the functional outcome of surgery undertaken.