C-arm tomography imaging method using semi-accurate filtered back-projection

Abstract

The invention discloses a tomography imaging method suitable for C-arm imaging equipment. The tomography imaging method is characterized by having shift invariant features, wherein the semi-accurate reconstruction is performed on cone-beam projection data obtained by scanning a circular arc track. The circular arc track is a short scanning track, namely a scanning track of pi and a fan angle, and is also an ultra-short scanning track, namely a track smaller than the short scanning track. The method comprises the following steps: weighing of partial derivatives of projection data; one-dimensional Hilbert transform in a horizontal or non-horizontal direction; and back projection of the circular arc track. Compared with FDK type-approximate reconstruction algorithms, the C-arm tomography imaging method using semi-accurate filtered back-projection has the advantages of small reconstruction accuracy error, small discretization error and the like.

Description

technical field [0001] The invention relates to a C-arm semi-precise filtering back-projection tomographic imaging method, which belongs to the field of biomedical imaging and is suitable for C-arm X-ray tomographic imaging. Background technique [0002] The C-arm imaging system is mainly composed of a C-arm, an X-ray source and a flat-panel detector installed at both ends of the C-arm. The X-ray optical signal emitted by the X-ray source forms a cone beam in space, and the C-arm can rotate around the horizontal axis in a limited space with a maximum angle range. At the same time, the flat panel detector can collect the X-ray attenuated light Signal. These light signals can in turn be converted into cone beam projection data, which can be used to reconstruct CT tomographic images. The C-arm with CT tomography function has important application value in clinical diagnosis and surgical evaluation, and is an important technology with broad application prospects. [0003] For...

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Problems solved by technology

Therefore, although the Katsevich type algorithm can obtain more accurate reconstruction results, the complex calculation process of the structure factor is not conducive to the parallel processing of the algorithm, thus reducing the computational efficiency of the reconstruction algorithm

In addition, Katsevich-type reconstruction algorithms have filter lines along the vertical or near-vertical direction at certain projection angles, while the algorithm proposed by Guang-Hong Chen et al. does not resample the projection data along the vertical direction of the detector. Affected the accuracy of the reconstruction results

The above two points are not conducive to the practical application of the Katsevich type cone beam reconstruction algorithm

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