An improved scatter correction method for Cone Beam Computed Tomography

Aiming at the scatter problem in Cone Beam Computed Tomography (CBCT) system, an improved scatter correction method based on Beam Attenuation Array (BAA) was proposed. In this method, BAA and filter plate are used as the scatter detection devices to scan 3 times and acquire 3 sets of projection images. The scatter values on the projection centers of the small ball array of BAA are calculated by using of the characteristic of a part of the ray attenuation caused by BAA, and then, the whole scatter intensity distribution covered the projection image, that is, the scatter image, is obtained by fitting these discrete scatter values on the projection centers of the small ball array. To complete the scatter correction, the final projection image is got by subtracting the corresponding scatter image from the original projection image. The experimental result shows that the improved method is practical and effective to correct the scatter in CBCT imaging systems, and the slice image quality is enhanced.