Strict Precision Cone-Beam CT Reconstruction Research Based On FDK Method

Cone-Beam CT reconstruction method is one of the most advanced subjects on the field of CT. Compared with 2D fan-beam CT it can achieve higher spatial resolution, higher scan speed and higher efficiency of X-ray. These advantages are very important in medical and non-destruction.Based on the characteristic of industrial flat-panel detector, In order to improve the quality of the image reconstructed with FDK method, Some research about improved FDK method and projection's disposal have been mentioned in this paper, also some research about helix PI-line method has been done in this paper.First of all, the methods of calculating the cone beam projection of two typical common 3D geometries are deduced. We also compared synthesizing projection with discrete volume projection, the cause of noise in the synthesized projections is analyzed, and then we improved calculating method. Later, based on the characteristic of industrial flat-panel detector, we improved 2D FBP method from 1D linear detector, and also improved FDK method based on volume. According to the theorem of Sampling, we improved the quality of projection that collected on the detector in the way of half-pixel staggered in the horizontal and vertical direction, and we got a good result in the experiment.At last, the condition of exact reconstruction and cone-beam helix reconstruction is mentioned in this paper. Especially some work about helix PI method was been done in this paper, and also we provide the simulation, analyzed its advantages and disadvantages, and give an elementary research about correlative work.