Research On Pi-line Algorithm Of Volume Ct Exact Reconstruction Image

Computer tomography (CT), especially spiral CT, has some important applications in medicine and industry for cross-sectional imaging. It is the paramount goal for human healthy to seek the minimum x-ray radiation in the field of the medical imaging. Indeed, low-dose imaging deteriorates image quality in the sense of prevailing image noise. Image artifacts stemming from the reconstruction process may cause erroneous diagnosis. A worthywhile effort is to propose some new reconstruction algorithms or to improve the existed ones for optimizing image reconstruction while maintaining low-dose condition. At present, commercial CT's adopt the algorithm of filtered back-projection (FBP) for image reconstruction. With a new imaging modality of volume CT appeared, a variety of volume reconstruction algorithms emerges in contempary medical imaging community. In this thesis, we study on the PI-line algorithm for volume CT reconstruction. Conventional spiral CT adopts FBP for image reconstruction has become a mature technology. The volume cone-beam scanning brings forth volume CT with the flat panel for x-ray detection. Therefore, the development of volume spiral CT needs the innovative algorithm for volume CT reconstruction.On the basis of the PI-line theory which is founded by Katsevich, the work of this thesis is done. The purpose of this research is mainly to provide the basis for the professional researcher by providing better image reconstruction algorithms and finding where the error is through the comparing study between the FDK algorithm and Katsevich algorithm.Such as parallel, fan (equiangular, offset), cone-beam and spiral algorithms, the various algorithms about CT in theory has been fairly complete. We get a result with a smaller error in the process of image reconstruction by computer, and then we can use the FDK algorithm and Katsevich algorithm to reconstruct the algorithm. At the same time, we can prove directly the correctness and accuracy of two algorithms in theory.The scanning mode for FDK reconstruction algorithm is:the effect of scanning objects along a circular path is equal to the fixed ray source and the detector, the objects rotating around rotary axis, the 3D reconstruction using the 2D projection sequence gained by the planar array detector. The Katsevich algorithm is to reconstruct directly on the basis of the 3D data sequence gained by the planar array detector.