OBJECTIVE: To assess the high-resolution CT scan in depicting the middle ear structures. METHOD: The surgical findings of 51 ears operated on were retrospectively compared with the CT findings. The followings were analysed: diagnostic features of chronic otitis media (COM) on CT status of the middle ear structures (ossicles, facial nerve canal, semicircular canals and tegmen tympani), and anatomical variations. RESULT: The radio-surgical agreement was excellent for the malleus (kappa statistics, k = 0.840) and tegmen (0.788), good for the incus (0.700) and semicircular canals (0.56), but poor for the stapes (0.366) and facial nerve dehiscence (0.310). Potential surgical hazards detected by the scans included: Low lying dura, high jugular bulb, anterior lying sigmoid sinus, facial nerve dehiscence and other situations brought about by the destructive nature of the lesion. CONCLUSION: There is a good radio-surgical correlation in COM for most middle ear structures except for the integrity of the facial canal and stapes. The scan alerts the surgeon the potential surgical dangers and complications of disease. High-resolution CT scan should be a routine examination prior to middle ear and mastoid surgery.
OBJECTIVE: To assess the high-resolution CT scan in depicting the middle ear structures. METHOD: The surgical findings of 51 ears operated on were retrospectively compared with the CT findings. The followings were analysed: diagnostic features of chronic otitis media (COM) on CT status of the middle ear structures (ossicles, facial nerve canal, semicircular canals and tegmen tympani), and anatomical variations. RESULT: The radio-surgical agreement was excellent for the malleus (kappa statistics, k = 0.840) and tegmen (0.788), good for the incus (0.700) and semicircular canals (0.56), but poor for the stapes (0.366) and facial nerve dehiscence (0.310). Potential surgical hazards detected by the scans included: Low lying dura, high jugular bulb, anterior lying sigmoid sinus, facial nerve dehiscence and other situations brought about by the destructive nature of the lesion. CONCLUSION: There is a good radio-surgical correlation in COM for most middle ear structures except for the integrity of the facial canal and stapes. The scan alerts the surgeon the potential surgical dangers and complications of disease. High-resolution CT scan should be a routine examination prior to middle ear and mastoid surgery.