Feasibility Study of Block-Matching and 3D Filtering Algorithm in Low-Dose CT Image with Tin Filter

The purpose of this study was to confirm the utility of block-matching and 3D filtering (BM3D) algorithm in computed tomography (CT) images using a tin filter with a high pitch. We acquired phantom images and measured the coefficient of variation (COV) and contrast-to-noise ratio (CNR) for quantitative evaluation. The optimized results were obtained when the sigma value of the BM3D algorithm was nine. In addition, when the sigma value of the optimized BM3D algorithm was applied, superior results were obtained compared with conventional filtering methods. In particular, we confirmed that the COV and CNR of the images obtained using the BM3D algorithm improved 6.52 and 5.49 times, respectively. In conclusion, the utility of the optimized BM3D algorithm has been demonstrated in low-dose CT images using a tin filter.