Imaging Diagnosis of Temporal Labyrinthitis and the Analysis of the Correlated Etiology

Objective:To study the imaging findings of labyrinthitis of temporal bone and to analyze the correlated etiology,in order to improve the understanding of this entity.Methods:41 patients with 55 ears had clinical history of otitis media,cholesteatoma,meningitis or trauma,ossified labyrinthitis was diagnosed by clinical examination and CT/MRI.The CT/MRI findings were analyzed retrospectively.Results:HRCT findings included high attenuated punctate,curvilinear densities in basal turns of cochlea or diffuse hyperattenuated cochlea with ground glass appearance and 24 ears associated with irregular narrowing of labyrinth cavities.Of these 24 ears,cochlear axis thickening was found in 2 ears,widening of bony spiral lamina in 2 ears and complete bony obliteration of cochlea in 4 ears.The manifestations of vestibule involvement included hyperattenuation and narrowing.Semicircular canals involvement manifested as increased density,narrowing of canal cavity or complete bony obliteration.Increased density and stricture of vestibular window and cochlear window meant involvement of these structures.The incidence rate of these structures involvement was transverse semicircular canal,posterior semicircular canal,cochlea,superior semicircular canal,vestibular window,cochlear window and vestibule successively.22 ears had abnormal MRI findings,showing iso-or hyperintensity on T1WI and decrease or disappearance of signal intensity on T2WI.Enhancement could be seen in early phase after contrast administration.The incidence rate of involvement was cochlea,transverse semicircular canal,superior semicircular canal,posterior semicircular canal and vestibule successively.Conclusion:CT and MRI examination were of significance in the diagnosis of ossified labyrinthitis as well as for defining the location of involvement.