title: Imaging of cochlear implant electrode array with flat-detector CT and conventional multislice CT: comparison of image quality and radiation dose.
abstract: CONCLUSIONS
  Cochlear implantation assessment is possible using commercially available standard flat-detector computed tomography (FD-CT) protocols. Image quality is superior to multislice CT (MSCT). The radiation dose of FD-CT is lower in comparison with MSCT standard protocols and may therefore overcome the limitations of MSCT in the evaluation of cochlear implants.
  
  
  OBJECTIVE
  FD-CT offers higher spatial resolution than MSCT. Our objective was to compare the image quality of FD-CT to conventional MSCT in the visualization of a cochlear implant electrode array with respect to radiation exposure.
  
  
  METHODS
  An isolated temporal bone specimen was scanned using a commercially available FD-CT system and a 4 and 64 row MSCT scanner. Different scanning protocols were used. Image quality was assessed by four independent readers using a scoring system with different criteria describing delineation of the cochlea and the electrode array, image noise and spatial resolution. Radiation dose was measured using the CT dose index (CTDI) and a 16 cm acrylic phantom.
  
  
  RESULTS
  Image quality was rated superior for FD-CT for all criteria by all readers. Single electrode contacts were only visible in FD-CT and assessment of implant position was improved by FD-CT. The radiation dose of FD-CT was half that of MSCT standard protocols.
authors.affiliation: Department of Neuroradiology, Institute of Medical Physics, University of Erlangen-Nuremberg, Schwabachanlage 6, Erlangen, Germany. tobias.struffert@uk-erlangen.de
authors.forename: Tobias
authors.initials: T
authors.lastname: Struffert
authors.forename: Victoria
authors.initials: V
authors.lastname: Hertel
authors.forename: Yannis
authors.initials: Y
authors.lastname: Kyriakou
authors.forename: Jens
authors.initials: J
authors.lastname: Krause
authors.forename: Tobias
authors.initials: T
authors.lastname: Engelhorn
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schick
authors.forename: Heinrich
authors.initials: H
authors.lastname: Iro
authors.forename: Joachim
authors.initials: J
authors.lastname: Hornung
authors.forename: Arnd
authors.initials: A
authors.lastname: Doerfler
mesh_terms: D016477:Artifacts; D003051:Cochlea / Q000000981:diagnostic imaging*; D003054:Cochlear Implants; D004558:Electric Stimulation / Q000379:methods; D004567:Electrodes, Implanted; D004867:Equipment Design; D005154:Facial Nerve / Q000000981:diagnostic imaging; D006311:Hearing Disorders / Q000628:therapy; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D008416:Mastoid / Q000000981:diagnostic imaging / Q000601:surgery; D011184:Postoperative Period; D011829:Radiation Dosage; D013137:Spiral Lamina / Q000000981:diagnostic imaging; D013701:Temporal Bone / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*; D014432:Tympanic Membrane / Q000000981:diagnostic imaging / Q000601:surgery