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

Jpn J Radiol. 2015 Nov;33(11):710-6. doi: 10.1007/s11604-015-0478-2. Epub 2015 Sep 24.

Abstract

Purpose: We compared the quality of the images acquired with single energy metal artifact reduction (SEMAR) on CT scans of three different human body areas.

Materials and 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.

Conclusion: Visual subjective evaluation showed that SEMAR improved the image quality.

Keywords: Artifact reduction; Metal implants; Noise.

MeSH terms

  • Algorithms*
  • Aneurysm / therapy
  • Artifacts*
  • Dental Prosthesis
  • Embolization, Therapeutic / instrumentation*
  • Hip Prosthesis
  • Humans
  • Metals
  • Prostheses and Implants*
  • Radiographic Image Enhancement / methods
  • Radiographic Image Interpretation, Computer-Assisted / methods*
  • Reproducibility of Results
  • Retrospective Studies
  • Sensitivity and Specificity
  • Tomography, X-Ray Computed / methods*

Substances

  • Metals