X-ray beam hardening correction based on polynomial fitting in local scanning

Beam hardening effect would be induced due to wide energy spectrum of X-ray. One efficient beam hardening correction method is building a mathematical law between poly energetic projection and intersection length, which can be calculated by forward projection in reconstructed images domain. However, for local scanning, the intersection length obtained by forward projection is no longer equal to the real distance at which X-ray passes through the object, and the data of mathematical fit are not valid. Hence, a cylindrical phantom is used. Utilizing the geometrical character of cylinder, the true distance X-ray passing through the object is calculated analytically. Experimental result shows that beam hardening artifacts are suppressed by our approach.