Establishment of normative cochlear and vestibular measurements to aid in the diagnosis of inner ear malformations.
OBJECTIVE
We sought to establish normative measurements of the inner ear using computed tomography (CT) of the temporal bone to aid in the diagnosis of inner ear malformations.


METHODS
Prospective measurements of the inner ear structures were made on axial and coronal temporal bone CT scans on 15 patients with normal hearing and 15 patients with sensorineural hearing loss.


RESULTS
The vertical height of the cochlea on coronal scan and the size of the central bony island within the lateral semicircular canal on axial scan along with visual inspection identified 7 inner ear abnormalities in 6 patients: 5 cases of lateral semicircular canal dysplasia and 2 cases of cochlear hypoplasia. In contrast, visual inspection alone identified only 4 of the 7 abnormalities.


CONCLUSIONS
Routine measurement of the cochlear height and bony island of the lateral semicircular canal, in conjunction with visual inspection of CT images, will increase recognition of common inner ear malformations.
Purcell
Derk
D
Department of Otolaryngology-Head and Neck Surgery, University of California San Francisco, 94143, USA.
Johnson
Jacob
J
Fischbein
Nancy
N
Lalwani
Anil K
AK
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003051:Cochlea / Q000000981:diagnostic imaging* / Q000473:pathology; D007758:Ear, Inner / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis*; D006320:Hearing Tests / Q000379:methods; D006801:Humans; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013701:Temporal Bone / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods*