title: Evaluation of the potential of phase-contrast computed tomography for improved visualization of cancerous human liver tissue.
abstract: OBJECTIVE
  Phase-contrast X-ray computed tomography (PCCT) is currently investigated and developed as a potentially very interesting extension of conventional CT, and can offer several advantages for specific indications in diagnostic imaging. Current absorption-based computed tomography (CT) without the application of contrast material is limited in the detection of minor density differences in soft-tissue. The purpose of this study is to test whether PCCT can improve soft tissue contrast in healthy and tumorous human liver specimens.
  
  
  METHODS
  Two specimens of human liver (one healthy and one metastasized liver sample) were imaged with brilliant X-ray beam at the synchrotron radiation source ESRF in Grenoble, France. For correlation the same specimens were imaged with a magnetic resonance imaging system at 1.5 T. The histopathology confirmed our findings in the corresponding sections of the specimens.
  
  
  RESULTS
  In the phase-contrast CT images we observed a significantly enhanced soft-tissue contrast when compared to simultaneously recorded standard absorption CT measurements. Further, we found that the pathological and morphological information in the PCCT reconstructions show significant improvement when compared to those performed on MRI. Based on matching of prominent features, a good correlation between PCCT and the histological section is demonstrated; especially the tumor capsule and the surrounding vascular structures are visible in PCCT. In addition, our study revealed the ability of PCCT to visualize the blood vessels structure in the tumorous liver without the need of any contrast agents.
  
  
  CONCLUSIONS
  Grating-based PCCT significantly improves the soft-tissue contrast in ex-vivo liver specimens and holds the potential to overcome the need of contrast materials for visualization of the tumor vascularization.
authors.affiliation: Department of Radiology, Technische Universität München, Munich, Germany. peter.noel@tum.de
authors.forename: Peter B
authors.initials: PB
authors.lastname: Noël
authors.forename: Julia
authors.initials: J
authors.lastname: Herzen
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Fingerle
authors.forename: Marian
authors.initials: M
authors.lastname: Willner
authors.forename: Marco K
authors.initials: MK
authors.lastname: Stockmar
authors.forename: Dieter
authors.initials: D
authors.lastname: Hahn
authors.forename: Marcus
authors.initials: M
authors.lastname: Settles
authors.forename: Enken
authors.initials: E
authors.lastname: Drecoll
authors.forename: Irene
authors.initials: I
authors.lastname: Zanette
authors.forename: Timm
authors.initials: T
authors.lastname: Weitkamp
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Rummeny
authors.forename: Franz
authors.initials: F
authors.lastname: Pfeiffer
mesh_terms: D005240:Feasibility Studies; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D015588:Observer Variation; D012031:Refractometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014961:X-Ray Diffraction / Q000379:methods*
keywords: Computertomographie; Röntgen-Phasen-Kontrast; Weichteilkontrast; X-ray phase contrast; cancer imaging; computed tomography; onkologische Bildgebung; soft-tissue contrast