European Radiology

, Volume 21, Issue 7, pp 1424–1429 | Cite as

Metal artifact reduction by dual energy computed tomography using monoenergetic extrapolation

  • Fabian Bamberg
  • Alexander Dierks
  • Konstantin Nikolaou
  • Maximilian F. Reiser
  • Christoph R. Becker
  • Thorsten R. C. Johnson
Computed Tomography

Abstract

Objective

The aim of the study was to assess the performance and diagnostic value of a dual energy CT approach to reduce metal artefacts in subjects with metallic implants.

Methods

31 patients were examined in the area of their metallic implants using a dual energy CT protocol (filtered 140 kVp and 100 kVp spectrum, tube current relation: 3:1). Specific post-processing was applied to generate energies of standard 120 and 140 kVp spectra as well as a filtered 140 kVp spectrum with mean photon energies of 64, 69 and 88 keV, respectively, and an optimized hard spectrum of 95–150 keV. Image quality and diagnostic value were subjectively and objectively determined.

Results

Image quality was rated superior to the standard image in 29/31 high energy reconstructions; the diagnostic value was rated superior in 27 patients. Image quality and diagnostic value scores improved significantly from 3.5 to 2.1 and from 3.6 to 1.9, respectively. In several exams decisive diagnostic features were only discernible in the high energy reconstructions. The density of the artefacts decreased from −882 to −341 HU.

Conclusions

Dual Energy CT with specific postprocessing can reduce metal artefacts and may significantly enhance diagnostic value in the evaluation of metallic implants.

Keywords

Metal artifacts Dual energy CT Computed tomography Quanta extrapolation 

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Copyright information

© European Society of Radiology 2011

Authors and Affiliations

  • Fabian Bamberg
    • 1
  • Alexander Dierks
    • 1
  • Konstantin Nikolaou
    • 1
  • Maximilian F. Reiser
    • 1
  • Christoph R. Becker
    • 1
  • Thorsten R. C. Johnson
    • 1
    • 2
  1. 1.Department of Clinical RadiologyLudwig-Maximilians UniversityMunichGermany
  2. 2.University of MunichMunichGermany

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