title: Monoenergetic imaging of dual-energy CT reduces artifacts from implanted metal orthopedic devices in patients with factures.
abstract: OBJECTIVE
  The purpose of this study was to optimize photon energy setting to reduce metal artifact of computed tomography (CT) images from implanted metal orthopedic devices in patients with fractures with monoenergetic imaging of dual-energy CT.
  
  
  METHODS
  This study included 47 patients with factures who underwent metal orthopedic device implanting. After dual-energy CT scan, monoenergetic software was used to postprocess with the following six photon energies: 40 kiloelectron-voltage (keV), 70 keV, 100 keV, 130 keV, 160 keV, and 190 keV. Two radiologists evaluated and rated the reformatted images with six different photon energies and average weighted 120 kVp images according to 4-score scale. The Wilcoxon rank-sum test was used to compare image quality scores for total, internal, and external metal orthopedic devices. Interreader agreement for image quality scoring was calculated.
  
  
  RESULTS
  Monoenergetic imaging of dual-energy CT improved the quality of CT images in the fracture patients with metal orthopedic devices compared to the average weighted 120 kVp images for the total, external, and internal metal orthopedic devices (all P values < .01). Optimal keV setting with the lowest metal artifact was 130 keV for total, internal, and external metal orthopedic devices. Good interreader agreement was found for the evaluation of image quality for total, internal, and external metal orthopedic devices.
  
  
  CONCLUSIONS
  Monoenergetic imaging of dual-energy CT improves quality of CT images in patients with metal orthopedic devices after fracture. Reformatted images at 130 keV have the optimal quality for total, internal, and external metal orthopedic devices.
authors: Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Xuanwu District, Jiangsu Province, China.
authors: Changsheng
authors: C
authors: Zhou
authors: Yan E
authors: YE
authors: Zhao
authors: Song
authors: S
authors: Luo
authors: Hongyuan
authors: H
authors: Shi
authors: Lin
authors: L
authors: Li
authors: Ling
authors: L
authors: Zheng
authors: Long Jiang
authors: LJ
authors: Zhang
authors: Guangming
authors: G
authors: Lu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D005260:Female; D050723:Fractures, Bone / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged; D019736:Prostheses and Implants; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012984:Software; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D008670:Metals