title: Computed tomographic features of the bony canal of the cochlear nerve in pediatric patients with unilateral sensorineural hearing loss.
abstract: OBJECTIVE
  The aim of this study was to evaluate the diameters of the various bony canals of the inner ear in patients with sensorineural hearing loss (SNHL) and establish criteria for detecting hypoplasia of the bony canal of the cochlear nerve.
  
  
  METHODS
  Measurements obtained in 118 patients without inner ear malformations among 160 patients with unilateral SNHL were analyzed. The diameters of the internal auditory canal and the bony canals of the cochlear, vestibular, and facial nerves were measured on transverse or coronal computed tomographic images. Mean values (+/- SD) were compared between the affected and unaffected ears, and statistical analysis was done.
  
  
  RESULTS
  The diameter of the bony canal of the cochlear nerve was significantly smaller in affected ears than in unaffected ears (P < 0.01). The affected ears could be divided into groups with (72 ears) and without (46 ears) bony canal stenosis.
  
  
  CONCLUSIONS
  Most (60%) of the patients with unilateral SNHL showed a significant difference in the diameters of the bony canals of the cochlear nerve between the affected and unaffected sides; moreover, the mean value was significantly smaller in affected ears. The diameter of < 1.7 mm on transverse images or < 1.8 mm on coronal images suggests hypoplasia.
authors.affiliation: Department of Radiology, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Shimotsuga, Tochigi 321-0293, Japan. t-kono@dokkyomed.ac.jp
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Kono
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003056:Cochlear Nerve / Q000000981:diagnostic imaging*; D007758:Ear, Inner / Q000000981:diagnostic imaging*; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D018709:Statistics, Nonparametric; D013701:Temporal Bone / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*