[High resolution computerized tomography of middle ear abnormalities].
BACKGROUND
The aim of this study was to analyze malformed petrous bones with computed tomography and to develop a radiologic score which can help to judge the indication for operative reconstructions.


METHODS
One hundred forty-two petrous bones in 71 patients with unilateral or bilateral microtia, atresia of the external auditory canal, and malformations of the middle ear were evaluated with high-resolution CT.


RESULTS
In 97% of patients with severe auricular dysplasia, there was dysplasia of the middle ear ossicles; in 70% the stapes was malformed. In 32% the oval window was occluded, and in 7% the round window. In 75%, the canal of the facial nerve was displaced, and 16% also showed abnormalities of the labyrinth. A close correlation between the malformation of the auricle and of the middle ear was not found.


CONCLUSIONS
High-resolution CT is necessary for the evaluation of malformed middle ears. Based on the abnormalities described, we propose a radiologic score for the assessment of malformed petrous bones. This consists of the following criteria: external auditory meatus, pneumatization of the mastoid and of the tympanic space, size of the tympanic space, facial nerve, vessels, malleus and incus, stapes, oval and round window. The graded points of each structure are added up to the score, which might range between 0 and 28. This score can help to judge the indication for reconstruction of the middle ear. In bilateral malformation we suggest a middle ear reconstruction of the better hearing ear if the score is greater than or equal to 15, and in unilateral malformation if it is at least 20. In patients with lower scores, we only suggest hearing aids.
Siegert
R
R
Klinik für Hals-, Nasen- und Ohrenheilkunde, Medizinischen Universität zu Lübeck.
Weerda
H
H
Mayer
T
T
Brückmann
H
H
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004429:Ear Ossicles / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000601:surgery; D004431:Ear, External / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery; D004432:Ear, Middle / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery; D005154:Facial Nerve / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006314:Hearing Loss, Conductive / Q000000981:diagnostic imaging / Q000235:genetics / Q000601:surgery; D006319:Hearing Loss, Sensorineural / Q000000981:diagnostic imaging / Q000235:genetics / Q000601:surgery; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D010046:Oval Window, Ear / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000601:surgery; D012405:Round Window, Ear / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000601:surgery; D013577:Syndrome; D014057:Tomography, X-Ray Computed
Hochauflösende Computer-tomographie fehlgebildeter Mittelohren.