title: Evaluation of the quality of CT images acquired with the single energy metal artifact reduction (SEMAR) algorithm in patients with hip and dental prostheses and aneurysm embolization coils.
abstract: OBJECTIVE
  We compared the quality of the images acquired with single energy metal artifact reduction (SEMAR) on CT scans of three different human body areas.
  
  
  METHODS
  Our institutional review board approved the study protocol. CT studies of 58 patients (hip prosthesis, n = 20; iliac artery aneurysm embolization, n = 20; dental prosthesis, n = 18) were retrospectively reconstructed using interactive reconstruction (IR) and IR plus SEMAR. Two radiologists independently evaluated the images for the reduction of metal artifacts at three sites, i.e., 0-1, 1-5, and 5-10 cm from their edges, and recorded their findings on a 100-mm-long line that corresponded to the Likert scale and ranged from 0 (invisible) to 100 mm (clearly visible). The standard deviation in Hounsfield units was used as the noise assessment tool. Statistical analysis was performed with the t test and the Wilcoxon signed-rank test.
  
  
  RESULTS
  The image quality of scans of hip prostheses and metal embolization coils was significantly improved when SEMAR was used (p < 0.05). On scans of dental prostheses, SEMAR did not contribute significantly, especially in the area 1 cm from the edge of the implant.
  
  
  CONCLUSIONS
  Visual subjective evaluation showed that SEMAR improved the image quality.
authors.affiliation: Department of Radiology, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga, 520-2192, Japan. akinaga@belle.shiga-med.ac.jp.|Department of Orthopedic Surgery, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga, 520-2192, Japan. akinaga@belle.shiga-med.ac.jp.
authors.forename: Akinaga
authors.initials: A
authors.lastname: Sonoda
authors.affiliation: Department of Orthopedic Surgery, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga, 520-2192, Japan. r34nitta@yahoo.co.jp.
authors.forename: Norihisa
authors.initials: N
authors.lastname: Nitta
authors.affiliation: Department of Orthopedic Surgery, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga, 520-2192, Japan. ushio@belle.shiga-med.ac.jp.
authors.forename: Noritoshi
authors.initials: N
authors.lastname: Ushio
authors.affiliation: Department of Orthopedic Surgery, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga, 520-2192, Japan. yatsushi@belle.shiga-med.ac.jp.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Nagatani
authors.affiliation: Department of Orthopedic Surgery, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga, 520-2192, Japan. noriaki@belle.shiga-med.ac.jp.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Okumura
authors.affiliation: Department of Orthopedic Surgery, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga, 520-2192, Japan. otani@belle.shiga-med.ac.jp.
authors.forename: Hideji
authors.initials: H
authors.lastname: Otani
authors.affiliation: Department of Orthopedic Surgery, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga, 520-2192, Japan. murata@belle.shiga-med.ac.jp.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Murata
mesh_terms: D000465:Algorithms; D000783:Aneurysm / Q000628:therapy; D016477:Artifacts; D017266:Dental Prosthesis; D004621:Embolization, Therapeutic / Q000295:instrumentation*; D006622:Hip Prosthesis; D006801:Humans; D008670:Metals; D019736:Prostheses and Implants; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D008670:Metals
keywords: Artifact reduction; Metal implants; Noise