title: Sensorineural hearing loss: there is no correlation with isolated dysplasia of the lateral semi-circular canal on temporal bone CT.
abstract: BACKGROUND
  Inner ear malformations may cause sensorineural hearing loss (SNHL). However, the correlation between the small lateral semi-circular canal (LSCC) and SNHL is controversial.
  
  
  OBJECTIVE
  To determine whether there is a correlation between the two using CT-based measurement.
  
  
  METHODS
  We retrospectively reviewed the high-resolution CT images of the temporal bone obtained from consecutive patients. A total 136 ears of 68 patients (25 men and 43 women; age range 20-85 years, mean 49.8 years) were included in this study. Patients who were clinically suspected to have otosclerosis were also excluded. Two radiologists independently measured the width and cross-sectional area of the bony island of LSCC. We evaluated the correlation between LSCC bone island width or cross-sectional area and hearing level in all cases using Pearson correlation co-efficients. In addition, we compared hearing levels among the patient group with normal-sized LSCC (≧mean-SD), small LSCC (<mean-SD) and very small LSCC (<mean-2SD) as defined by the width and cross-sectional area of the bony island using Student's t-test.
  
  
  RESULTS
  A total 136 ears of 68 patients (25 men and 43 women; age range 20-85 years, mean 49.8 years) were included in this study. No significant correlation was shown between LSCC bony island width or cross-sectional area and hearing level (P > 0.05). No significant difference in hearing levels were found among groups of the normal-sized, small and very small LSCC (P > 0.05).
  
  
  CONCLUSIONS
  We conclude that there is no correlation between isolated small LSCC and SNHL.
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Maidashi, Higashi-ku, Fukuoka, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Yamashita
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshiura
authors.forename: Akio
authors.initials: A
authors.lastname: Hiwatashi
authors.forename: Dashjamts
authors.initials: D
authors.lastname: Tuvshinjargal
authors.forename: Hironori
authors.initials: H
authors.lastname: Kamano
authors.forename: Takashi
authors.initials: T
authors.lastname: Inoguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Honda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001837:Body Weights and Measures / Q000379:methods; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012189:Retrospective Studies; D012665:Semicircular Canals / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D013701:Temporal Bone / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult