Computed tomography in diagnosis of otosclerosis

Abstract Objectives: To identify the main tomographic findings of otosclerosis and to evaluate the utility of the high resolution computed tomography (HRCT) as a diagnostic method and therapeutic indicator of this osteodystrophy. Methods: A prospective and multicentric study using computed tomography (CT) of the temporal bone in 54 patients with a clinical and surgical diagnosis of otosclerosis. In this study, 22 patients who had undergone CT scans of temporal bones have been included in order to investigate other otologic diseases and have constituted the control group. A tomographic analysis has been performed to evaluate the sensitivity of CT scans in diagnosing otosclerosis, verifying the sites of predilection for otosclerotic lesions, the bilateralism and symmetry of the disease. We have researched the possible correlations among the tomographic findings and gender, evolution of the disease, family history, and type of the hearing loss of the patients. Results: The CT scan was positive in 87% of the patients. The tomographic findings were mostly bilateral and the fenestral focuses were more prevalent, mainly the anterior focus to the oval window. The disease evolution time was longer in the patients with mixed (fenestral and retrofenestral) and/or multiple otosclerotic focuses. Conclusions: The CT scan has shown a high index of positivity, mainly in the fenestral lesions. The anterior focus to the oval window has been the most prevalent in this population, and it could be considered the highly suggestive tomographic finding for otosclerosis. The evolution time of this disease has been longer in patients with diffuse focuses in the otic capsule.