title: Translation of atherosclerotic plaque phase-contrast CT imaging from synchrotron radiation to a conventional lab-based X-ray source.
abstract: OBJECTIVE
  Phase-contrast imaging is a novel X-ray based technique that provides enhanced soft tissue contrast. The aim of this study was to evaluate the feasibility of visualizing human carotid arteries by grating-based phase-contrast tomography (PC-CT) at two different experimental set-ups: (i) applying synchrotron radiation and (ii) using a conventional X-ray tube.
  
  
  METHODS
  Five ex-vivo carotid artery specimens were examined with PC-CT either at the European Synchrotron Radiation Facility using a monochromatic X-ray beam (2 specimens; 23 keV; pixel size 5.4 µm), or at a laboratory set-up on a conventional X-ray tube (3 specimens; 35-40 kVp; 70 mA; pixel size 100 µm). Tomographic images were reconstructed and compared to histopathology. Two independent readers determined vessel dimensions and one reader determined signal-to-noise ratios (SNR) between PC-CT and absorption images.
  
  
  RESULTS
  In total, 51 sections were included in the analysis. Images from both set-ups provided sufficient contrast to differentiate individual vessel layers. All PCI-based measurements strongly predicted but significantly overestimated lumen, intima and vessel wall area for both the synchrotron and the laboratory-based measurements as compared with histology (all p<0.001 with slope >0.53 per mm(2), 95%-CI: 0.35 to 0.70). Although synchrotron-based images were characterized by higher SNRs than laboratory-based images; both PC-CT set-ups had superior SNRs compared to corresponding conventional absorption-based images (p<0.001). Inter-reader reproducibility was excellent (ICCs >0.98 and >0.84 for synchrotron and for laboratory-based measurements; respectively).
  
  
  CONCLUSIONS
  Experimental PC-CT of carotid specimens is feasible with both synchrotron and conventional X-ray sources, producing high-resolution images suitable for vessel characterization and atherosclerosis research.
authors.affiliation: Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Saam
authors.forename: Julia
authors.initials: J
authors.lastname: Herzen
authors.forename: Holger
authors.initials: H
authors.lastname: Hetterich
authors.forename: Sandra
authors.initials: S
authors.lastname: Fill
authors.forename: Marian
authors.initials: M
authors.lastname: Willner
authors.forename: Marco
authors.initials: M
authors.lastname: Stockmar
authors.forename: Klaus
authors.initials: K
authors.lastname: Achterhold
authors.forename: Irene
authors.initials: I
authors.lastname: Zanette
authors.forename: Timm
authors.initials: T
authors.lastname: Weitkamp
authors.forename: Ulrich
authors.initials: U
authors.lastname: Schüller
authors.forename: Sigrid
authors.initials: S
authors.lastname: Auweter
authors.forename: Silvia
authors.initials: S
authors.lastname: Adam-Neumair
authors.forename: Konstantin
authors.initials: K
authors.lastname: Nikolaou
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Franz
authors.initials: F
authors.lastname: Pfeiffer
authors.forename: Fabian
authors.initials: F
authors.lastname: Bamberg
mesh_terms: D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000473:pathology; D004867:Equipment Design; D006801:Humans; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000473:pathology; D015203:Reproducibility of Results; D017356:Synchrotrons / Q000295:instrumentation*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*
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