title: Preclinical evaluation by flat-panel detector-based volumetric CT versus MRI of intervertebral spacers implanted in a porcine model.
abstract: BACKGROUND
  Image quality and implant detectability by conventional imaging methods are suboptimal for perioperative spinal diagnostics, primarily limited by implant-related artifacts.
  
  
  OBJECTIVE
  To evaluate the imaging quality of various intervertebral spacers examined by flat-panel detector-based volumetric computed tomography (FD-VCT) versus magnetic resonance imaging (MRI).
  
  
  METHODS
  A preclinical comparative study on an experimental porcine model. The study was performed at a university research facility.
  
  
  METHODS
  Three different intervertebral spacer types (titanium, carbon fiber-reinforced polymer, cobalt-chrome-molybdenum) were implanted in a cadaveric porcine spine and then examined by MRI using T1-weighted spin echo (T1w-SE) and turbo spin echo (T1w-TSE) sequences. Comparative imaging was performed with an experimentally approved FD-VCT prototype featuring two-dimensional and three-dimensional imaging and high isotropic spatial resolution. Data analysis focused on spacer shape, implant positioning, and implant-bone interface.
  
  
  RESULTS
  Compared with MRI, and despite the use of T1w-SE and T1w-TSE sequences, the image quality and detectability of all target characteristics were better with FD-VCT absent the usual artifacts. Using its option for implant-specific imaging, the experimental FD-VCT imager allowed reliable determination of additional variables such as dimension and volume.
  
  
  CONCLUSIONS
  This experimental study provides initial evidence that FD-VCT produces excellently sharp, high-accuracy, artifact-free imaging quality that is superior to MRI in distinguishing key characteristics of intervertebral implants in a preclinical setting.
authors.affiliation: Department of Orthopedic Surgery, University of Gottingen, Robert-Koch-Strasse 40, 37075 Gottingen, Germany. ternstberger@med.uni-goettingen.de
authors.forename: Thorsten
authors.initials: T
authors.lastname: Ernstberger
authors.forename: Gabert
authors.initials: G
authors.lastname: Heidrich
authors.forename: Christian
authors.initials: C
authors.lastname: Dullin
authors.forename: Gottfried
authors.initials: G
authors.lastname: Buchhorn
authors.forename: Eckhardt
authors.initials: E
authors.lastname: Grabbe
mesh_terms: D000818:Animals; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D009984:Orthopedic Fixation Devices; D013131:Spine / Q000000981:diagnostic imaging* / Q000601:surgery*; D013552:Swine; D014057:Tomography, X-Ray Computed