Labyrinthitis ossificans is ossification of the inner ear structures. Patients present with profound irreversible hearing loss. LO can be diagnosed definitively on imaging with CT, which shows ossification of the membranous labyrinth, and can be suggested on MRI, which shows loss of normal fluid signal in the inner ear. In the acute/subacute stage of labyrinthitis without ossification, MRI shows enhancement of the membranous labyrinth. Imaging findings are important for treatment guidance (selection of appropriate patients for cochlear implantation) and for prognostication.

From the manuscript

Labyrinthitis and Labyrinthitis Ossificans - A case report and review of the literature

Abstract
Labyrinthitis most commonly results from an infectious and less commonly from an inflammatory process of the inner ear, but it can be associated with temporal bone trauma, hemorrhage, or tumor. This inflammation (regardless of the etiology) disrupts the transmission of sensory information from the ear to the brain. Labyrinthitis ossificans is the pathological ossification of the membranous labyrinthine spaces in response to an insult to the inner ear involving membranous labyrinth or the endosteum of the otic capsule. Herein, we present a case of a 67-year-old female with progressive bilateral sensorineural hearing loss and positional vertigo.