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European Radiology

, Volume 20, Issue 9, pp 2126–2134 | Cite as

Spectroscopic (multi-energy) CT distinguishes iodine and barium contrast material in MICE

  • N. G. Anderson
  • A. P. Butler
  • N. J. A. Scott
  • N. J. Cook
  • J. S. Butzer
  • N. Schleich
  • M. Firsching
  • R. Grasset
  • N. de Ruiter
  • M. Campbell
  • P. H. Butler
Computed Tomography

Abstract

Objective

Spectral CT differs from dual-energy CT by using a conventional X-ray tube and a photon-counting detector. We wished to produce 3D spectroscopic images of mice that distinguished calcium, iodine and barium.

Methods

We developed a desktop spectral CT, dubbed MARS, based around the Medipix2 photon-counting energy-discriminating detector. The single conventional X-ray tube operated at constant voltage (75 kVp) and constant current (150 µA). We anaesthetised with ketamine six black mice (C57BL/6). We introduced iodinated contrast material and barium sulphate into the vascular system, alimentary tract and respiratory tract as we euthanised them. The mice were preserved in resin and imaged at four detector energy levels from 12 keV to 42 keV to include the K-edges of iodine (33.0 keV) and barium (37.4 keV). Principal component analysis was applied to reconstructed images to identify components with independent energy response, then displayed in 2D and 3D.

Results

Iodinated and barium contrast material was spectrally distinct from soft tissue and bone in all six mice. Calcium, iodine and barium were displayed as separate channels on 3D colour images at <55 µm isotropic voxels.

Conclusion

Spectral CT distinguishes contrast agents with K-edges only 4 keV apart. Multi-contrast imaging and molecular CT are potential future applications.

Keywords

Medipix CT spectroscopy Spectral CT K-edge imaging Contrast material Photon counting detector 

Notes

Acknowledgements

We thank the Medipix2 and Medipix3 collaborations and European Organisation for Nuclear Research (CERN) for use of the Medipix detectors; Graeme Kershaw for fixing the mice in the resin; Judith Dawson for help preparing the manuscript; Steffi Girst for dose estimation.

This work was supported by FRST-Man grant PROJ-13860-NMTS-UOC.

This information was presented at the European Congress of Radiology, March, 2009

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Copyright information

© European Society of Radiology 2010

Authors and Affiliations

  • N. G. Anderson
    • 1
  • A. P. Butler
    • 1
    • 2
  • N. J. A. Scott
    • 3
  • N. J. Cook
    • 4
  • J. S. Butzer
    • 5
  • N. Schleich
    • 2
    • 4
  • M. Firsching
    • 6
  • R. Grasset
    • 7
  • N. de Ruiter
    • 7
  • M. Campbell
    • 8
  • P. H. Butler
    • 2
  1. 1.Department of RadiologyUniversity of OtagoChristchurchNew Zealand
  2. 2.Physics and AstronomyUniversity of CanterburyChristchurchNew Zealand
  3. 3.Department of MedicineUniversity of OtagoChristchurchNew Zealand
  4. 4.Medical Physics and BioengineeringChristchurch HospitalChristchurchNew Zealand
  5. 5.Physics DepartmentKarlsruhe Institute of TechnologyKarlsruheGermany
  6. 6.Physics DepartmentFriedrich Alexander UniversityErlangenGermany
  7. 7.Hitlab NZUniversity of CanterburyChristchurchNew Zealand
  8. 8.Physics SectionEuropean Organisation for Nuclear ResearchGenevaSwitzerland

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