Cochlear Otosclerosis

History: 30 year old female with a history of hearing loss.

Single nonenhanced coronal CT through the temporal bones shows a lucent halo of diffuse demineralization around the right cochlear bony labyrinth.

The term for this finding is cochlear otosclerosis. Synonyms include cochlear otospongiosis, retrofenestral otosclerosis, and Beethoven Malady. The diagnosis in this case was osteogenesis imperfecta, however, paget disease, fibrous dysplasia, and otosyphillis can cause these findings.