The Effect of Metal Artifact Reduction at Different Calibrated and Display Field of Views in Computed Tomography.

Abstract

The purpose of this study was to investigate the effects of the metal artifact reduction using single energy metal artifact reduction (SEMAR) with a prosthetic hip joint in different field of view (FOV). A prosthetic hip joint was arranged at the center of the phantom. The phantom images were scanned by changing calibrated-FOV (C-FOV) of 240, 320, 400, and 500 mm. Those images were reconstructed by changing the display-FOV (D-FOV) of 120, 180, 240, and 320 mm. The metal artifact reduction with the SEMAR was evaluated by calculating the artifact index (AI) and its decrease ratio. The AI of C-FOV (500 mm) and D-FOV (120, 180, 240, or 320 mm) were 15.8, 15.8, 15.7, and 14.4 with SEMAR. For changed C-FOV, the AI of C-FOV (240 mm) was significantly higher than any other C-FOVs. The AI of C-FOV (240 mm) was 29.8-30.0 and that of the other C-FOV were 12.4-15.8 with SEMAR. In addition, the decrease ratio of AI was 52.2-54.1% for C-FOV (240 mm) and 58.9-73.2% for the other C-FOVs. Although the SEMAR decreased the metal artifact, the effect of reducing the metal artifact was affected by C-FOV.