European Radiology

, Volume 22, Issue 6, pp 1331–1340 | Cite as

Metal artefact reduction in gemstone spectral imaging dual-energy CT with and without metal artefact reduction software

  • Young Han Lee
  • Kwan Kyu Park
  • Ho-Taek Song
  • Sungjun Kim
  • Jin-Suck SuhEmail author



To assess the usefulness of gemstone spectral imaging (GSI) dual-energy CT (DECT) with/without metal artefact reduction software (MARs).


The DECTs were performed using fast kV-switching GSI between 80 and 140 kV. The CT data were retro-reconstructed with/without MARs, by different displayed fields-of-view (DFOV), and with synthesised monochromatic energy in the range 40–140 keV. A phantom study of size and CT numbers was performed in a titanium plate and a stainless steel plate. A clinical study was performed in 26 patients with metallic hardware. All images were retrospectively reviewed in terms of the visualisation of periprosthetic regions and the severity of beam-hardening artefacts by using a five-point scale.


The GSI-MARs reconstruction can markedly reduce the metal-related artefacts, and the image quality was affected by the prosthesis composition and DFOV. The spectral CT numbers of the prosthesis and periprosthetic regions showed different patterns on stainless steel and titanium plates.


Dual-energy CT with GSI-MARs can reduce metal-related artefacts and improve the delineation of the prosthesis and periprosthetic region. We should be cautious when using GSI-MARs because the image quality was affected by the prosthesis composition, energy (in keV) and DFOV. The metallic composition and size should be considered in metallic imaging with GSI-MARs reconstruction.

Key Points

• Metal-related artefacts can be troublesome on musculoskeletal computed tomography (CT).

• Gemstone spectral imaging (GSI) with dual-energy CT (DECT) offers a novel solution

• GSI and metallic artefact reduction software (GSI-MAR) can markedly reduce these artefacts.

• However image quality is influenced by the prosthesis composition and other parameters.

• We should be aware about potential overcorrection when using GSI-MARs.


Dual-energy CT Computed tomography Metallic artefacts 



This study was supported by a faculty research grant of Yonsei University College of Medicine (6-2008-0223).


  1. 1.
    National Hospital Discharge Survey: survey results and products. Atlanta: Centers for Disease Control and Prevention, 2009. (Accessed May 5, 2011, at .
  2. 2.
    White LM, Buckwalter KA (2002) Technical considerations: CT and MR imaging in the postoperative orthopedic patient. Semin Musculoskelet Radiol 6:5–17PubMedCrossRefGoogle Scholar
  3. 3.
    Barrett JF, Keat N (2004) Artifacts in CT: recognition and avoidance. Radiographics 24:1679–1691PubMedCrossRefGoogle Scholar
  4. 4.
    Haramati N, Staron RB, Mazel-Sperling K et al (1994) CT scans through metal scanning technique versus hardware composition. Comput Med Imaging Graph 18:429–434PubMedCrossRefGoogle Scholar
  5. 5.
    Love C, Marwin SE, Palestro CJ (2009) Nuclear medicine and the infected joint replacement. Semin Nucl Med 39:66–78PubMedCrossRefGoogle Scholar
  6. 6.
    Buck FM, Jost B, Hodler J (2008) Shoulder arthroplasty. Eur Radiol 18:2937–2948PubMedCrossRefGoogle Scholar
  7. 7.
    Gelman MI, Coleman RE, Stevens PM, Davey BW (1978) Radiography, radionuclide imaging, and arthrography in the evaluation of total hip and knee replacement. Radiology 128:677–682PubMedGoogle Scholar
  8. 8.
    Phillips WC, Kattapuram SV (1983) Efficacy of preoperative hip aspiration performed in the radiology department. Clin Orthop Relat Res 141–146Google Scholar
  9. 9.
    Young SW, Muller HH, Marshall WH (1983) Computed tomography: beam hardening and environmental density artifact. Radiology 148:279–283PubMedGoogle Scholar
  10. 10.
    Lee MJ, Kim S, Lee SA et al (2007) Overcoming artifacts from metallic orthopedic implants at high-field-strength MR imaging and multi-detector CT. Radiographics 27:791–803PubMedCrossRefGoogle Scholar
  11. 11.
    Watzke O, Kalender WA (2004) A pragmatic approach to metal artifact reduction in CT: merging of metal artifact reduced images. Eur Radiol 14:849–856PubMedCrossRefGoogle Scholar
  12. 12.
    Li H, Yu L, Liu X, Fletcher JG, McCollough CH (2010) Metal artifact suppression from reformatted projections in multislice helical CT using dual-front active contours. Med Phys 37:5155–5164PubMedCrossRefGoogle Scholar
  13. 13.
    Li H, Yu L, Liu X, McCollough CH (2009) Metal artifact suppression from reformatted projections in multi-slice helical CT using dual-front active contours. Conf Proc IEEE Eng Med Biol Soc 2009:993–996PubMedGoogle Scholar
  14. 14.
    Yu L, Li H, Mueller J et al (2009) Metal artifact reduction from reformatted projections for hip prostheses in multislice helical computed tomography: techniques and initial clinical results. Invest Radiol 44:691–696PubMedCrossRefGoogle Scholar
  15. 15.
    Link TM, Berning W, Scherf S et al (2000) CT of metal implants: reduction of artifacts using an extended CT scale technique. J Comput Assist Tomogr 24:165–172PubMedCrossRefGoogle Scholar
  16. 16.
    Montner SM, Lehr JL, Oravez WT (1987) Quantitative evaluation of a dual energy CT system. J Comput Assist Tomogr 11:144–150PubMedCrossRefGoogle Scholar
  17. 17.
    Dilmanian FA (1992) Computed tomography with monochromatic x rays. Am J Physiol Imaging 7:175–193PubMedGoogle Scholar
  18. 18.
    Dilmanian FA, Wu XY, Parsons EC et al (1997) Single-and dual-energy CT with monochromatic synchrotron x-rays. Phys Med Biol 42:371–387PubMedCrossRefGoogle Scholar
  19. 19.
    Bamberg F, Dierks A, Nikolaou K, Reiser MF, Becker CR, Johnson TR (2011) Metal artifact reduction by dual energy computed tomography using monoenergetic extrapolation. Eur Radiol 21:1424–1429PubMedCrossRefGoogle Scholar
  20. 20.
    Boas FE, Fleischmann D (2011) Evaluation of two iterative techniques for reducing metal artifacts in computed tomography. Radiology 259:894–902PubMedCrossRefGoogle Scholar
  21. 21.
    Lin XZ, Miao F, Li JY, Dong HP, Shen Y, Chen KM (2011) High-definition CT Gemstone spectral imaging of the brain: initial results of selecting optimal monochromatic image for beam-hardening artifacts and image noise reduction. J Comput Assist Tomogr 35:294–297PubMedCrossRefGoogle Scholar
  22. 22.
    Zhang D, Li X, Liu B (2011) Objective characterization of GE discovery CT750 HD scanner: gemstone spectral imaging mode. Med Phys 38:1178–1188PubMedCrossRefGoogle Scholar
  23. 23.
    Douglas-Akinwande AC, Buckwalter KA, Rydberg J, Rankin JL, Choplin RH (2006) Multichannel CT: evaluating the spine in postoperative patients with orthopedic hardware. Radiographics 26:S97–S110PubMedCrossRefGoogle Scholar

Copyright information

© European Society of Radiology 2012

Authors and Affiliations

  • Young Han Lee
    • 1
  • Kwan Kyu Park
    • 2
  • Ho-Taek Song
    • 1
  • Sungjun Kim
    • 1
  • Jin-Suck Suh
    • 1
    Email author
  1. 1.Department of Radiology, Research Institute of Radiological Science, Medical Convergence Research Institute, and Severance Biomedical Science InstituteYonsei University College of MedicineSeoulRepublic of Korea
  2. 2.Department of Orthopaedic SurgeryYonsei University College of MedicineSeoulRepublic of Korea

Personalised recommendations