Analytical SPECT reconstruction algorithm for helical cone-beam geometry using ray-driven technology

2012 ◽  
Author(s):  
Kangping Zhang ◽  
Junhai Wen ◽  
Cuifen Li ◽  
Rui Yang ◽  
Haixiang Dong ◽  
...  
Keyword(s):  
Reconstruction Algorithm ◽  
Cone Beam ◽  
Beam Geometry ◽  
Spect Reconstruction

A new weighting scheme for arc based circle cone-beam CT reconstruction

2021 ◽  
pp. 1-19
Author(s):  
Wei Wang ◽  
Xiang-Gen Xia ◽  
Chuanjiang He ◽  
Zemin Ren ◽  
Jian Lu
Keyword(s):  
Characteristic Function ◽  
Weighting Function ◽  
Cone Beam Ct ◽  
Reconstruction Algorithm ◽  
Cone Beam ◽  
Characteristic Functions ◽  
Projection Data ◽  
Ct Reconstruction ◽  
Scanning Angle ◽  
Beam Geometry

In this paper, we present an arc based fan-beam computed tomography (CT) reconstruction algorithm by applying Katsevich’s helical CT image reconstruction formula to 2D fan-beam CT scanning data. Specifically, we propose a new weighting function to deal with the redundant data. Our weighting function ϖ ( x _ , λ ) is an average of two characteristic functions, where each characteristic function indicates whether the projection data of the scanning angle contributes to the intensity of the pixel x _ . In fact, for every pixel x _ , our method uses the projection data of two scanning angle intervals to reconstruct its intensity, where one interval contains the starting angle and another contains the end angle. Each interval corresponds to a characteristic function. By extending the fan-beam algorithm to the circle cone-beam geometry, we also obtain a new circle cone-beam CT reconstruction algorithm. To verify the effectiveness of our method, the simulated experiments are performed for 2D fan-beam geometry with straight line detectors and 3D circle cone-beam geometry with flat-plan detectors, where the simulated sinograms are generated by the open-source software “ASTRA toolbox.” We compare our method with the other existing algorithms. Our experimental results show that our new method yields the lowest root-mean-square-error (RMSE) and the highest structural-similarity (SSIM) for both reconstructed 2D and 3D fan-beam CT images.

Near Real-Time X-Ray Cone-Beam Microtomography

1999 ◽  
Vol 5 (S2) ◽  
pp. 940-941
Author(s):  
Shih Ang ◽  
Wang Ge ◽  
Cheng Ping-Chin
Keyword(s):  
Reconstruction Algorithm ◽  
Cone Beam ◽  
Reconstruction Process ◽  
X Ray ◽  
Beam Geometry ◽  
Cone Beam Reconstruction ◽  
Cylindrical Coordinate ◽  
Contrast Mechanism ◽  
Penetration Ability ◽  
Set Up

Due to the penetration ability and absorption contrast mechanism, cone-beam X-ray microtomography is a powerful tool in studying 3D microstructures in opaque specimens. In contrast to the conventional parallel and fan-beam geometry, the cone-beam tomography set up is highly desirable for faster data acquisition, build-in magnification, better radiation utilization and easier hardware implementation. However, the major draw back of the cone-beam reconstruction is its computational complexity. In an effort to maximize the reconstruction speed, we have developed a generalized Feldkamp cone-beam reconstruction algorithm to optimize the reconstruction process. We report here the use of curved voxels in a cylindrical coordinate system and mapping tables to further improve the reconstruction efficiency.The generalized Feldkamp cone-beam image reconstruction algorithm is reformulated utilizing mapping table in the discrete domain as: , where .

A cone beam SPECT reconstruction algorithm with a displaced center of rotation

1994 ◽  
Vol 21 (1) ◽  
pp. 145-152 ◽  
Author(s):  
Jianying Li ◽  
Ronald J. Jaszczak ◽  
Huili Wang ◽  
Grant T. Gullberg ◽  
Kim L. Greer ◽  
...  
Keyword(s):  
Reconstruction Algorithm ◽  
Cone Beam ◽  
Center Of Rotation ◽  
Spect Reconstruction

Isotope computed tomography using cone-beam geometry: a comparison of two reconstruction algorithms

1987 ◽  
Vol 32 (10) ◽  
pp. 1221-1235 ◽  
Author(s):  
A Horsman ◽  
J Sutcliffe ◽  
L Burkinshaw ◽  
P Wild ◽  
J Skilling ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cone Beam ◽  
Reconstruction Algorithms ◽  
Beam Geometry
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