VALUE OF COMPUTED-TOMOGRAPHY (CT) IN THE DIAGNOSIS OF COCHLEAR OTOSCLEROSIS

The temporal bones of 40 patients with surgically confirmed otoscleros is were studied with high-resolution CT. The hearing of these patients was re-examined 5 years later. Foci of demineralization in the cochle ar capsule were detected in 36% of operated ears and in 44% of otoscle rotic ears not operated on. Mean bone conduction (BC) thresholds of ea rs with positive radiological findings did not differ significantly fr om those of otosclerotic ears with normal CT, either at the time of CT examination or 5 years later. Over 5 years, elevation of BC threshold s by 10 dB or more was observed significantly more often in operated e ars with abnormal CT than in operated ears with normal CT, but in otos clerotic ears not operated on the corresponding difference was non-sig nificant. It was concluded that CT examination is of little value in p redicting sensorineural hearing loss in patients with otosclerosis.