title: Appearance and Frequency of Gas Interface Artifacts Involving Small Bowel on Rapid-Voltage-Switching Dual-Energy CT Iodine-Density Images.
abstract: OBJECTIVE
  The purpose of this study is to describe the appearance and frequency of gas interface artifacts in the jejunum that may mimic severe bowel disease on iodine-density images generated from rapid-voltage-switching dual-energy CT (DECT) scans.
  
  
  METHODS
  Two readers retrospectively reviewed 108 consecutive abdominal rapid-voltage-switching DECT scans to record the presence of image artifacts in jejunal segments with different degrees of gaseous luminal filling, classified as full, partial, or absent. Readers viewed iodine-density images and corresponding 140-kVp and 65-keV virtual monochromatic images and classified the jejunal artifacts on iodine-density images as pseudostratified appearance of the bowel wall, pseudopneumatosis, pseudohyperenhancement, or pseudohypoenhancement. We correlated the presence of the artifacts with clinical features suggesting bowel disease.
  
  
  RESULTS
  Image artifacts were found in 91 of 108 scans (84.3%), appeared in 148 of 265 jejunal segments (55.8%), and included each type except for pseudohypoenhancement. Artifacts occurred exclusively when gas was present in the bowel lumen and were seen in 59 of 59 (100%) fully gas-distended segments, 89 of 98 (90.8%) partially gas-distended segments, and none of 108 gas-absent segments (p < 0.0001). In fully and partially gas-distended jejunal segments (n = 157), 148 (94.3%) segments had two or more artifacts. None of the patients was found to have clinical bowel-related injury on follow-up of medical records.
  
  
  CONCLUSIONS
  Pseudostratified appearance, pseudopneumatosis, and pseudohyperenhancement, but not pseudohypoenhancement, artifacts are common in gas-filled jejunal segments on iodine-density images generated from rapid-voltage-switching DECT scans and are not seen in the corresponding 140-kVp or 65-keV images. Knowledge of the appearance of such iodine-density image artifacts will avoid potential examination interpretation pitfalls.
authors.affiliation: 1 Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University College of Medicine, Taoyuan County, Taiwan.
authors.forename: En-Haw
authors.initials: EH
authors.lastname: Wu
authors.affiliation: 2 Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Kim
authors.affiliation: 3 Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628.
authors.forename: Z Jane
authors.initials: ZJ
authors.lastname: Wang
authors.affiliation: 4 Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan.
authors.forename: Wei-Chou
authors.initials: WC
authors.lastname: Chang
authors.affiliation: 5 Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
authors.forename: Li-Qin
authors.initials: LQ
authors.lastname: Zhao
authors.affiliation: 3 Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Yeh
mesh_terms: D016477:Artifacts; D003287:Contrast Media; D005740:Gases; D006801:Humans; D007455:Iodine; D007583:Jejunum / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D005740:Gases; D007455:Iodine
keywords: DECT; artifact; dual-energy CT; jejunum; small bowel