Head and Neck ImagingTympanosclerosis
irreversible, nonspecific end-result of chronic
inflammation and traumatic events to the tympanic membrane and
middle ear. It is characterized by submucosal collagenesis and hyalinization, and finally
calcification and occassionally ossification. Sometimes the term myringosclerosis is used when the process is limited to the tympanic membrane, while tympanosclerosis indicates involvement of the
ossicular chain. These patients suffer from
conductive hearing loss. As these patients have a prologned history of otitis media, the diagnosis is usually made on clinical grounds. However, in some patients with an intact tympanic membrane, it may be difficult to clinically differentiate this condition from
otosclerosis; the whitish discoloration of the tympanic membrane by the calcium deposits may sometimes clinically mimic the appearance of a
cholesteatoma.
CT is useful to confirm the diagnosis and establish the disease extent, which is important to know as the success of surgery heavily depends upon it. Myringosclerosis can be diagnosed when a thickened and calcified tympanic membrane is seen (Fig.1). The diagnosis of tympanosclerosis can strictly speaking only be made when middle ear calcifications, surrounding the ossicular chain, are seen (Fig.2). If nondependent soft tissue thickening, without calcifications, is seen around the ossicular chain in a patient with severe conductive hearing loss, the condition would instead be called fibroadhesive chronic otitis media.
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Coronal CT image of left temporal bone. Some tympanic membrane calcifications are present (arrows): myringosclerosis. Soft tissue thickening in the mesotympanon, pronounced new bone formation in the epitympanon (asterisk), surrounding the upper part of the ossicular chain (arrowhead): tympanosclerosis.
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Tympanosclerosis, Fig.1 | | Tympanosclerosis, Fig.2 | |