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

Abstract

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.

CT Grading of Otosclerosis

“…Some authors have successfully correlated the frequency of hearing loss with the location of involvement of the cochlear capsule. 25,26 This suggests a local effect by the otosclerotic foci on that part of the cochlea. However, other authors have postulated that the sensorineural hearing loss is a result of cytotoxic enzymes causing hyalinization of the spiral ligament, 27,28 in which case there may be no correlation between the exact location of a lytic focus on the cochlea and the frequency of hearing loss.…”

Relationship between CT densitometry with a slice thickness of 0.5 mm and audiometry in otosclerosis

“…Areas of radiolucency may be seen to be mixed with sclerotic changes in otosclerosis [6]. Because it may not be possible to diagnose this remineralized phase using CT [19], the macroscopic diagnosis of otosclerosis is sometimes difficult. Therefore, we attempted to determine the appropriate cutoff HU value by ROC analysis.…”

“…Although the CT densitometry of fenestral otosclerosis and the correlation between CT densitometry and audiometry have been reported [16][17][18][19][20][21][22], there have been few reports concerning CT densitometry or the cutoff value for the diagnosis of otosclerosis using CT images with a slice thickness of 0.5 mm.…”

Magnetic Resonance Imaging and High-Resolution Computed Tomography in the Otospongiotic Phase of Otosclerosis

“…The result might be a chronic inflammation with an initial osteolytic phase called otospongiosis. In the further course of the disease, otosclerosis in a narrow sense must be interpreted as a kind of postinflammatory scarring [5,6].…”