Reduction of Metal Artifact in X-ray CT by Quartic-Polynomial Interpolation
用四次多项式插值消除医用X射线CT中的金属伪影

Nowadays X ray computerized tomography has been one of the most important diagnostic tools in medicine. However, sometimes the metallic implants absorb the X rays and therefore introduce streaks on the reconstructed images, which interfere diagnosis severely. In this paper, a simple interpolation method using quartic polynomials to fill in the missing projections is presented. The clipping on the pixel values of the reconstructed image is also proposed. The polynomial is determined by several criteria, namely smooth transition at the ends of the gap of missing projections, being as linear as possible inside the gap, and constant sum of interpolated projections in every direction. Value clipping eliminates irrational pixel values by evaluating the distribution of pixel values. Experiments show that by our method, the streaks caused by the metallic implants can be greatly suppressed and the contrast can be significantly improved.