Evaluation of the Effects of Differences in Metal Artifact Type and Location on Image Quality in Computed Tomography Scans

Se-Won Lim; Woo-Keun Choi; Sungchul Kim

doi:10.4103/jmp.jmp_87_22

Evaluation of the Effects of Differences in Metal Artifact Type and Location on Image Quality in Computed Tomography Scans

J Med Phys. 2023 Jan-Mar;48(1):80-84. doi: 10.4103/jmp.jmp_87_22. Epub 2023 Apr 18.

Authors

Se-Won Lim¹, Woo-Keun Choi², Sungchul Kim¹

Affiliations

¹ Department of Radiological Science, Gachon University Medical Campus, Hambangmoe-ro, Incheon, Korea.
² Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

Abstract

Artifacts in computed tomography scans distort anatomical information and prevent an accurate diagnosis. Therefore, this study aims to determine the most effective method for reducing metal-induced artifacts by evaluating the effects of the metal artifact type and location, and the tube voltage on the image quality. Fe and Cu wires were inserted into a Virtual Water™ phantom at 6.5 and 11 cm distances from the center point (DPs). The contrast-to-noise ratios (CNRs) and signal-to-noise ratios (SNRs) were calculated to compare the images. The results reveal higher CNRs and SNRs when using standard and Smart metal artifact reduction (Smart MAR) algorithms for Cu and Fe insertions, respectively. The standard algorithm leads to a higher CNR and SNR for Fe and Cu at DPs of 6.5 and 11 cm, respectively. The Smart MAR algorithm provides effective outcomes at voltages of 100 and 120 kVp for wires located at 11 and 6.5 cm DP, respectively. The most effective imaging conditions for MAR is generated by the Smart MAR algorithm with a tube voltage for 100 kVp for Fe located at a DP of 11 cm. MAR can be improved by setting suitable tube voltage conditions according to the type and location of inserted metal.

Keywords: Contrast-to-noise ratio; metal artifact; signal-to-noise ratio; smart metal artifact reduction algorithm; standard algorithm.