1. A method for eliminating an artifact of a computed tomography image, comprising: eliminating a machine artifact from a cross-sectional computed tomography image of the brain; setting boundary points positioned on a horizontal axis and a vertical axis in the computed tomography image, from which the machine artifact has been eliminated; resetting a boundary point positioned at a boundary between the skull of the brain and the brain tissue based on the boundary points; detecting a position of a fracture of the brain in the computed tomography image, in which the boundary point has been reset, and overlaying a fracture region with a skull pixel; and eliminating an artifact from the computed tomography image, which has been overlaid with the skull pixel.