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

Purpose: 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).

Methods: 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.

Results: 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.

Conclusion: Although the SEMAR decreased the metal artifact, the effect of reducing the metal artifact was affected by C-FOV.