Comparison of quantitative measurements of four manufacturer’s metal artifact reduction techniques for CT imaging with a self-made acrylic phantom

BACKGROUND: Metal artifact reduction (MAR) techniques can improve metal artifacts of computed tomography (CT) images. OBJECTIVE: This work focused on conducting a quantitative analysis to compare the effectiveness of four commercial MAR techniques on three types of metal implants (hip implant, spinal implant, and dental filling) with a self-made acrylic phantom. METHODS: A cylindrical phantom was made from acrylic with a groove in the middle, and then three types of metal implants were placed in the groove. The phantom was scanned by four CT scanners and four commercialized MAR techniques were used to analyze the images. The techniques used were single-energy metal artifact reduction (SEMAR, Canon), smart metal artifact reduction software (Smart-MAR, GE), iterative metal artifact reduction (IMAR, Siemens), and metal artifact reduction for orthopedic implants (OMAR, Philips). Quantitative analysis methods included objective and subjective analysis. RESULTS: The expected value of SEMAR, Smart-MAR, IMAR, and OMAR were 36.6, 37.8, 5.0, and 2.3, respectively. SEMAR and Smart-MAR achieved optimal results. CONCLUSION: This study successfully evaluated the effects of four commercial MAR techniques on three types of metal implants in a phantom. All MAR techniques effectively reduced metal artifacts, but the effect was not significant with dental fillings due to high-density material.