Sensitivity and Specificity of High-Resolution Computed Tomography (HRCT) of Temporal Bone in Diagnosing Cholesteatoma and Its Correlation with Intraoperative Findings.

High resolution computed tomography (HRCT) of temporal bone helps in understanding the complex anatomy of temporal bone and in identifying disease in temporal bone. However, its role in diagnosing cholesteatoma and analyzing its extent and complications is not established unequivocally. Present study was undertaken to check sensitivity and specificity of HRCT in diagnosing cholesteatoma and assessing its extent and in identifying ossicular destruction and other complications. In this prospective study in 50 patients with clinical diagnosis of cholesteatoma, preoperative high-resolution temporal bone CT scans axial and coronal view were carried out and compared with intra-operative findings. Kappa statistics was used for radio-surgical correlation. Comparison of CT scan findings with intraoperative findings revealed perfect correlation for sigmoid plate erosion, mastoid cortex dehiscence and scutum erosion, strong correlation for erosion of malleus, posterior superior wall and peri labyrinthine cells, good for erosion of incus and stapes, labyrinthine fistula, tegmen erosion and extent of disease and moderate correlation for facial canal dehiscence. HRCT scan of the temporal bone is useful preoperative investigation for cholesteatoma surgery for identification and documentation of ossicular status, location and extent of disease, erosion of tegmen or sinus or labyrinthine dehiscence, with the exception of facial canal dehiscence. Although it serves as road map for surgery, it still has some false positives and false negatives and the importance of a skilful, aware and alert surgeon cannot be overemphasized.