[The importance of computed tomography examination of temporal bone in detecting tympanosclerosis].

Objectives: The aim of this study was to show detectability of tympanosclerotic plaques with computed tomography (CT) which has an important role in the evaluation of temporal bone.

Patients And Methods: Our study group included 19 tympanoplasty cases (12 females, 7 males; mean age 31 years; range 12 to 57 years) who were operated on for hearing restoration due to chronic otitis media and conductive hearing loss between January 2006 and May 2006 at the Department of Otolaryngology, Head and Neck Surgery, Izmir Atatürk Training and Research Hospital. The tympanosclerotic plaques obtained from surgical specimens were sent for pathological confirmation and temporal bone CT scans which were obtained preoperatively were reevaluated by a blinded radiologist who was dealing with head and neck radiology.

Results: All histopathological specimens obtained from tympanosclerotic plaques showed hyaline degeneration and increased collagen formation, resulting in increased epithelial thickness, calcification and in some cases ossification. Tympanosclerosis was identified in CT scans as ossified or calcified high density regions in the soft tissue in middle ear cavity, leading to ovoid, linear or weblike forms. Of those 19 cases, who were unilaterally operated on, eight cases had findings suggestive of tympanosclerosis in CT only in tympanic membrane (42.1%), two in only middle ear (10.5%) and eight in both middle ear and tympanic membrane (42.1%). In only one case (5.2%), tympanosclerosis was not identified radiologically.

Conclusion: This study shows that temporal bone CT scan is a valuable method to diagnose the etiology of hearing loss and to detect the localization of the tympanosclerosis, in patients with chronic otitis media and conductive hearing loss. When combined with clinical findings, CT scans can be an informative guide to otolaryngologists for preoperative evaluation of tympanosclerosis.