Computed Tomography Findings of Otosclerosis

Aim: High-resolution computed tomography (HRCT) is the radiological method of choice in the assessment of the labyrinthine windows and otic capsule. The objective of the present study is to identify the main tomographic findings of otosclerosis and to evaluate the usefulness of HRCT as a diagnostic method for otosclerosis.

Material: A radiological, prospective study was conducted on 18 patients (36 ears) with otosclerosis including 12 women (66.7%) and 6 men (33.3%). Age ranged from 25 to 59 years, with a mean of 42.8 years. Duration of the disease ranged from 6 months to 30 years, with a mean of 8.5 years.

Method: The diagnosis of otosclerosis was made based on a combination of family history, conductive hearing loss pattern, and surgical confirmation. All patients were submitted to HRCT axial and coronal CT section (section thickness, 1 to 2 mm; increment, 1 mm) was obtained. The exams were analyzed and discussed together with a radiologist.

Results: A family history of otosclerosis was negative in 10 patients (55.5%) and positive in 8 (44.5%). In the present study, CT was able to identify otosclerotic foci in 15 patients (83.3%) or 27 ears (75%). The tomographic findings were bilateral in 60% of these patients, with bilateral and symmetric foci being observed in 46.66%. Evidence of diffuse otosclerotic foci on CT scans was not correlated with age, sex, family history of otosclerosis, or type of hearing loss.

Conclusion: CT was efficient in the diagnosis of otosclerotic foci, showing a high rate of positivity, especially for fenestral lesions.