Labyrinthine ossification: etiologies and CT findings.

Abstract

Ossification of the membranous labyrinth (labyrinthitis ossificans) develops as the final result of many inflammatory processes, for example, meningitis, blood-borne septic emboli, middle ear infection, and cholesteatoma. Labyrinthine ossification may also occur as a result of previous labyrinthectomy or secondary to trauma. Seven cases of labyrinthine ossification accompanied by severe vertigo and total hearing loss in the affected ear are discussed. The computed tomographic appearance of varying degrees of ossification, the clinical and surgical circumstances from which this disorder may develop, and the various approaches to labyrinthectomy are described.

Intralabyrinthine Schwannomas: Imaging Diagnosis and Classification

“…On a thinsection temporal bone CT scan, there will be bony encroachment on the membranous labyrinth. [32][33][34][35] None of our patients with presumed ILS had a history of prior meningitis or otomastoiditis. Although it is possible to confuse the early imaging of labyrinthine ossificans with ILS, the clinical setting helps separate these entities.…”

Clinical and Radiologic Findings of Inner Ear Involvement in Sickle Cell Disease

“…The characteristic imaging finding of LO is ossification of the membranous labyrinth on high resolution CT. On high resolution T2-weighted imaging, the normal T2 hyperintensity in the labyrinth is lost. 3,9,12,[16][17][18][19][20] There was no LO case with gadolinium enhanced MR imaging in our study. Postcontrast-enhanced characteristics of LO has not been described well in the literature.…”

“…Postcontrast-enhanced characteristics of LO has not been described well in the literature. 3,9,[16][17][18][19][20] The enhancing labyrinth occurs most commonly in the acute and subacute stage of labyrinthitis due to accumulation of gadolinium within inflamed labyrinthine membrane. LO is the end-stage of labyrinthitis and characterized pathologically by proliferation of fibroblasts and finally osteoblasts.…”

“…12,[16][17][18][19][20] In postmeningitic LO, the most common location has been reported to be the scala tympani of the basal turn of cochlea due to the route of inflammation spread through the cochlear aqueduct. [16][17][18][19][20] The LSC also is reported to be affected frequently in the patients with more advanced ossification. 18 The difference between LO in SCD and LO secondary to other etiologies may be the initially affected location.…”

“…In postmeningitic LO, the inner ear is sometimes affected bilaterally due to the spread of the infection by CSF. [16][17][18][19][20] Given that vaso-occlusion in patients with SCD can occur within any organ and that the labyrinthine artery has a higher chance of vaso-occlusion given the small caliber of this vessel, the observation of bilateral involvement by LO in patients with SCD is not surprising.…”