title: Cone-beam computed tomography in children with cochlear implants: The effect of electrode array position on ECAP.
abstract: OBJECTIVE
  To assess the feasibility of using cone-beam computed tomography (CBCT) in young children with cochlear implants (CIs) and study the effect of intracochlear position on electrophysiological and behavioral measurements.
  
  
  METHODS
  A total of 40 children with either unilateral or bilateral cochlear implants were prospectively included in the study. Electrode placement and insertion angles were studied in 55 Cochlear®implants (16 straight arrays and 39 perimodiolar arrays), using either CBCT or X-ray imaging. CBCT or X-ray imaging were scheduled when the children were leaving the recovery room. We recorded intraoperative and postoperative neural response telemetry threshold (T-NRT) values, intraoperative and postoperative electrode impedance values, as well as behavioral T (threshold) and C (comfort) levels on electrodes 1, 5, 10, 15 and 20.
  
  
  RESULTS
  CBCT imaging was feasible without any sedation in 24 children (60%). Accidental scala vestibuli insertion was observed in 3 out of 24 implants as assessed by CBCT. The mean insertion angle was 339.7°±35.8°. The use of a perimodiolar array led to higher angles of insertion, lower postoperative T-NRT, as well as decreased behavioral T and C levels. We found no significant effect of either electrode array position or angle of insertion on electrophysiological data.
  
  
  CONCLUSIONS
  CBCT appears to be a reliable tool for anatomical assessment of young children with CIs. Intracochlear position had no significant effect on the electrically evoked compound action potential (ECAP) threshold. Our CBCT protocol must be improved to increase the rate of successful investigations.
authors.affiliation: Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France. Electronic address: m-lathuilliere@chu-montpellier.fr.
authors.forename: Marine
authors.initials: M
authors.lastname: Lathuillière
authors.affiliation: Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Merklen
authors.affiliation: Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Piron
authors.affiliation: Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France.
authors.forename: Marielle
authors.initials: M
authors.lastname: Sicard
authors.affiliation: Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Villemus
authors.affiliation: Neuroradiology Department, University Hospital Gui-de-Chauliac, Montpellier, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Menjot de Champfleur
authors.affiliation: Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Venail
authors.affiliation: Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Uziel
authors.affiliation: Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Mondain
mesh_terms: D002675:Child, Preschool; D019929:Cochlear Implantation; D003054:Cochlear Implants; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D017097:Electric Impedance; D055724:Electrophysiological Phenomena; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011184:Postoperative Period; D012533:Scala Tympani / Q000000981:diagnostic imaging*; D054738:Scala Vestibuli / Q000000981:diagnostic imaging*; D016896:Treatment Outcome
keywords: Children; Cochlear implant; Cone-beam CT; ECAP; Electrode array; Insertion angle