title: Visualisation of passive middle ear implants by cone beam and multi-detector computed tomography: a comparative in vitro study.
abstract: OBJECTIVE
  Modern passive middle ear titanium prostheses are filigree structures, resulting in poorer depiction on CT compared to prostheses used in the past. We compared the visibility of newer prostheses on cone beam CT (CBCT) to multi-detector CT (MDCT) with standard and lower dose in vitro, and analysed image noise and metal artefacts.
  
  
  METHODS
  Six different titanium middle ear prostheses (three partial and one total ossicular replacement prostheses, two stapes prostheses) were implanted twice in formalin-fixed head specimens-first correctly and then with displacement. Imaging was performed using standard CBCT and MDCT as well as MDCT with lower dose (36 single imaging investigations). Images were analysed with knowledge of the used types of middle ear prostheses, but blinded with respect to the positioning in the specific case.
  
  
  RESULTS
  On all images the type of prostheses and their positions could be clearly recognized. Their identifiability including their details was rated as statistically significantly higher for all CBCT investigations than for MDCT. MDCT with lower dose showed the worst results. No statistical differences were found in image noise and metal artefacts.
  
  
  CONCLUSIONS
  If available, CBCT should be preferred over MDCT in diagnostic evaluation of passive middle ear prostheses.
  
  
  CONCLUSIONS
  • Middle ear prostheses became more filigree, leading to poorer visibility on CT. • High spatial resolution and paraxial reconstructions are necessary requirements for imaging evaluation. • CBCT and MDCT can identify type and positioning of titanium prostheses. • Metal artefacts play a minor part in filigree titanium prostheses. • Regarding visualisation of prostheses details, cone beam CT aids the evaluation.
authors.affiliation: Department of Radiology, University of Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle Saale, Germany. t-d-n@gmx.de.
authors.forename: T D
authors.initials: TD
authors.lastname: Nguyen
authors.affiliation: Department of Radiology, University of Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle Saale, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Kösling
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery "Otto Körner", Doberaner Straße 137-139, 18057, Rostock, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Mlynski
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery,, University of Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle Saale, Germany.
authors.forename: S K
authors.initials: SK
authors.lastname: Plontke
mesh_terms: D016477:Artifacts; D054893:Cone-Beam Computed Tomography; D004432:Ear, Middle / Q000000981:diagnostic imaging*; D046089:Hearing Loss, Mixed Conductive-Sensorineural / Q000601:surgery; D006801:Humans; D061330:Multidetector Computed Tomography; D009998:Ossicular Prosthesis; D019933:Ossicular Replacement / Q000379:methods*; D019047:Phantoms, Imaging
keywords: Cone beam CT; Human cadaver specimen; Middle ear prosthesis; Multi-detector CT; Passive implant