title: The cochlear nerve canal and internal auditory canal in children with normal cochlea but cochlear nerve deficiency.
abstract: BACKGROUND
  There is an increasing frequency of requests for cochlear implantation (CI) in deaf children and more detailed image information is necessary for selecting appropriate candidates. Cochlear nerve deficiency (CND) is a contraindication to CI. Magnetic resonance imaging (MRI) has been used to evaluate the integrity of the cochlear nerve. The abnormalities of the cochlear nerve canal (CNC) and internal auditory canal (IAC) have been reported to be associated with CND.
  
  
  OBJECTIVE
  To correlate CNC manifestation, size, and IAC diameter on high-resolution CT (HRCT) with CND diagnosed by MRI in children.
  
  
  METHODS
  HRCT images from 35 sensorineurally deaf children who had normal cochlea but bilateral or unilateral CND diagnosed by MRI were studied retrospectively. The CNC and IAC manifestation and size were assessed and correlated with CND.
  
  
  RESULTS
  CND was diagnosed by MRI in 54/70 ears (77.1%). Thirty-two ears had an absent cochlear nerve (59.3%), while 22 ears had a small cochlear nerve (40.7%). The CNC diameter was <1.5 mm in 36 ears (66.7%). The CNC diameter ranged between 1.5 and 2.0 mm in seven ears (13.0%) and was >2.0 mm in 11 ears (20.4%). The IAC diameter was <3.0 mm in 25 ears (46.3%) and >3.0 mm in 29 ears (53.7%).
  
  
  CONCLUSIONS
  The hypoplastic CNC might be more highly indicative of CND than that of a narrow IAC.
authors: Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors: Fei
authors: F
authors: Yan
authors: Jianhong
authors: J
authors: Li
authors: Junfang
authors: J
authors: Xian
authors: Zhenchang
authors: Z
authors: Wang
authors: Lingyan
authors: L
authors: Mo
mesh_terms: D000293:Adolescent; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D003051:Cochlea / Q000000981:diagnostic imaging / Q000473:pathology*; D003056:Cochlear Nerve / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000473:pathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012189:Retrospective Studies; D013701:Temporal Bone / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods*