A New Cone-beam Reconstruction Algorithm Based on Planar Detector
一种新的基于平面检测器的锥形束体积重建算法

Cone-beam reconstruction, which is also called volumetric reconstruction, has been one of the central research problems in medical imaging. Compared with traditional 3D reconstruction, it has several advantages, such as faster scanning, better dose usage and the isotropy of the spatial resolution and density resolution in 3D reconstruction object. Based on the idea of Grass's T-FDK algorithm, a new volumetric reconstruction algorithm named FT-FDK, was presented in this paper. The X-ray projection data were collected on a planar detector instead of a cylinder detector, which was quite different from Grass's algorithm. The 2D projects were obtained along a single circular source trajectory. Unlike traditional FDK algorithm, there were three steps in this new algorithm. The first step was that the projection data should be rebinned to oblique parallel projection data. Then, the rebinned oblique parallel projection data should be pre-weighting filtered. And the last step was that filtered projection data should be backprojected to the final 3D reconstructed image data. Theory and experimental results indicated that this algorithm had the same computational complexity as traditional FDK algorithm and the image quality was improved in the reconstruction. The results suggest that this algorithm can be used widely in applications of medical imaging and nondestructive testing.