Fenestral and cochlear otosclerosis: computed tomographic evaluation.

Computed tomography has replaced conventional multidirectional tomography in the imaging of patients with the presumed diagnosis of otosclerosis. In addition to obliterative disease, which was easily diagnosed with multidirectional tomography, anterior and posterior foci of varying sizes can now also be visualized preoperatively. Active cochlear otosclerosis (otospongiosis) is diagnosed in the presence of foci of demineralization in the otic capsule. Diagnosis of these entities has been of great interest to our referring otologic surgeons.

The vestibular aqueduct syndrome: computed tomographic appearance.

We have recently examined three young patients with congenital unilateral profound sensorineural hearing loss. On computed tomography the only abnormality discovered was a remarkably enlarged vestibular aqueduct on the abnormal side. The vestibular aqueduct syndrome is an important cause of congenital hearing loss. Although this finding has been well illustrated with conventional multidirectional tomography, there has been little emphasis on the computed tomographic appearance.

Cochlear otosclerosis (otospongiosis): CT analysis with audiometric correlation.

Ninety patients who had suspected or confirmed fenestral or cochlear otosclerosis underwent CT examination. Foci of demineralization in the otic capsule were discovered in 20 ears (12 patients). Audiometric studies of the 12 patients revealed sensorineural hearing loss (SNHL) with distinct correlation of CT findings with progressivity and with involvement of the frequency level subtended by the specific area of the cochlea involved. Foci of abnormal increased density, presumably representing the healed phase of this disorder, were found less frequently than expected. There was a predilection for the basilar turn. All patients had static SNHL in the higher frequencies. The healed phase of this disorder is probably not consistently diagnosable with CT.