Cone beam CT three-dimensional reconstruction method and system

Abstract

The invention provides a cone beam CT three-dimensional reconstruction method and system. A mode of GPU acceleration is adopted, at the same time, the amount of calculation is reduced by using geometric symmetry, a thread is established for a connection line between each pixel and a ray source, the length of the connection line in each voxel in volume data is calculated, thus an x optimal solutionis obtained through an iterative method, a purpose of efficient three-dimensional reconstruction is achieved, and the computational efficiency is greatly improved while the quality of a reconstruction image is guaranteed.

Description

technical field [0001] The present invention relates to reconstruction algorithm technology in the technical field of X-ray CT, in particular to a cone-beam CT three-dimensional reconstruction method and system. Background technique [0002] Compared with traditional CT technology, flat-panel detectors have higher image resolution and larger FOV, so cone-beam CT using flat-panel detector technology has more advantages in imaging quality and imaging efficiency. Therefore, how to quickly and accurately perform 3D reconstruction under the cone-beam CT model has become a very important issue. [0003] Patents CN104899903A, CN102609978A, and CN102279970A provide 3D reconstruction based on FDK algorithm. As a filter back projection accumulation algorithm, although the calculation speed is fast and the system resource requirements are low, the quality of the reconstructed image is poor, and there are artifacts, which affect the visualization effect and doctor's diagnosis. [0004...

AI Technical Summary

Problems solved by technology

The ART algorithm needs to calculate the projection matrix. At present, the algorithm proposed by Siddon et al. is usually used. This algorithm is a point-by-point calculation method, that is, the position of the upper and lower points of the ray is judged according to the relative position relationship between a certain point on the ray and the voxel to be reconstructed. The amount of calculation is Larger and lower computational efficiency, especially when the volume data to be reconstructed is three-dimensional, the defect is more obvious, which limits the clinical application of ART algorithms

Although there are some improved algorithms, most of them use approximate assumptions, such as only judging whether the ray passes through the voxel, and the crossing is recorded as 1, otherwise the 01 approximation method recorded as 0 will affect the accuracy of the projection matrix

[0005] The filtered back-projection algorithm represented by the FDK algorithm has a fast calculation speed and low requirements on system resources, but the quality of the reconstructed image is poor and there are artifacts, which affect the visualization effect and doctor's diagnosis

The ART algorithm needs to calculate the projection matrix. At present, the algorithm proposed by Siddon et al. is usually used. This algorithm is a point-by-point calculation method, that is, the position of the upper and lower points of the ray is judged according to the relative position relationship between a certain point on the ray and the voxel to be reconstructed. The amount of calculation is Larger and lower computational efficiency, especially when the volume data to be reconstructed is three-dimensional, the defect is more obvious, which limits the clinical application of ART algorithms

Although there are some improved algorithms, most of them use approximate assumptions, such as only judging whether the ray passes through the voxel, and the crossing is recorded as 1, otherwise the 01 approximation method recorded as 0 will affect the accuracy of the projection matrix

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