Metal Artifact Reduction in Routine Chest and Abdominal Examinations Using Virtual Monoenergetic Images From Spectral Detector Computed Tomography

Objective The objective of this study was to investigate the quantitative and qualitative effects of virtual monoenergetic images (VMIs) by spectral detector computed tomography (SDCT) on metal artifacts in routine examinations. Methods Fifty-nine patients with metal artifacts (caused by pacemakers, ports, screws, or prosthetic joints) affecting muscular tissue in the chest and/or abdomen were scanned using SDCT. Attenuation values around the metallic device were compared with contralateral unaffected values, for conventional images and 80 to 200 keV VMIs. In addition, general image quality and artifact intensity were rated by 2 readers. Results The VMIs significantly decreased metal artifact intensity in all patients (P < 0.05). In 39 patients (66.1%), the attenuation values of the artifact and the unaffected area on the optimal keV level were very similar (<= 5 Hounsfield unit difference). Qualitative analysis showed that high VMIs significantly improved artifact intensity, with best scores at 140 keV. Conclusions High monoenergetic images of SDCT significantly reduce metal artifacts, with optimal assessment at 140 keV.