Studies On The Analytic Reconstruction Algorithm For Variable Pitch Spiral Cone-beam CT

Spiral cone-beam CT is widely applied in the medical and industrial non-destructivetesting field, because it has not only fast data acquisition speed, higher utilization efficiencyof the rays, uniform axial distribution, but also can solve the problem of long objection. Butthe problem of Z-axis resolution with spiral CT has been restricted its engineering application.And in the existing imaging system, with the limit of sampling frequency and detector probesize, the innovation of scan mode has become the only effective way to solve the Z-axisresolution of helical CT. So this paper presents variable pitch spiral cone-beam reconstructionto solve the problem.To improve the reconstructed image resolution of helical scanning, the pitch of helicalscanning to the influence of rebuilding image resolution is specifically studied. And, therelationship between detector probe size and pitch as well as image resolution to improvesampling frequency of projection data is discussed. The paper puts forward that smaller pitchscan reconstruction is the effective method to detect the object of subtle information.According to the conclusion, it studies the variable pitch scanning strategy based on the prioriof internal structure of the detected object and the FDK reconstruction algorithm.With the same time of research in theory, through the simulation and comparativeanalysis, the method of imaging with variable pitch helical FDK reconstruction is provedeffectiveness. From the results, we can conclude that variable pitch helical scan reconstructioncan effectively improve the Z-axis resolution in the certain imaging system.