Study of Parallel Translation Computed Laminography Imaging
(2.Engineering Research Center of Industrial Computed Tomography Nondestructive Testing, Ministry of Education, Chongqing University, Chongqing, China 400044)
【Abstract】The computed laminography (CL) system has a unique advantage in aspects of large and plate-like objects imaging. We propose the parallel translation computed laminography (PTCL) system. Then, aiming at the image reconstruction of the system, the Feldkamp, Davis and Kress (FDK) algorithm is applied in the system. Due to the limited size of the detector, the system can only collect the projections of the region of interest of the object and the the total variation minimization based simultaneous algebraic reconstruction technique (SART + TV) algorithm is introduced into the object imaging. The simulation and experimental results demonstrate that both FDK and proposed method can achieve image reconstruction for PTCL. Compared with the FDK algorithm, the proposed method can reconstruct high-quality images from truncated and region of interest projections. Furtherly, it also demonstrates the feasibility of the system.
【Keywords】 imaging systems; computed laminography imaging; image reconstruction; linear scanning; plate-like objects;
(Translated by CAI ZJ)
 Gondrom S, Schropfer S. Digital computed laminography and tomosynthesis-functional principles and industrial applications [J]. Journalof Nondestructive Testing & Ultrasonics (Germany), 1999, 7 (2): 75–81.
 Wakimoto K, Blunt J, Carlos C, et al. Digital laminography assessment of the damage in concrete exposed to freezing temperatures [J]. Cement and Concrete Research, 2008, 38 (10): 1232–1245.
 des Plantes B G Z. Eine neue methode zur differenzierung in der rontgenographie (planigraphies) [J]. Acta Radiologica, 1932, 13 (2): 182–192.
 Grant D G. Tomosynthesis: a three-dimensional radiographic imaging technique [J]. IEEE Transactions on Biomedical Engineering, 1972, BME-19 (1): 20–28.
 O′Brien N S, Boardman R P, Sinclair I, et al. Recent advances in X-ray cone-beam computed laminography [J]. Journal of X-Ray Science and Technology, 2016, 24 (5): 691–707.
 Zhou J, Maisl M, Reiter H, et al. Computed laminography for materials testing [J]. Applied Physics Letters, 1996, 68 (24): 3500–3502.
 Sechopoulos I. A review of breast tomosynthesis. Part I. The image acquisition process [J]. Medical Physics, 2013, 40 (1): 014301.
 Sechopoulos I. A review of breast tomosynthesis. Part II. Image reconstruction, processing and analysis, and advanced applications [J]. Medical Physics, 2013, 40 (1): 014302.
 Maisl M, Porsch F, Schorr C. Computed laminography for X-ray inspection of lightweight constructions [J]. 2nd International Symposium on NDT in Aerospace, 2010: 2–8.
 Fu J, Jiang B H, Li B. Large field of view computed laminography with the asymmetric rotational scanning geometry [J]. Science China Technological Sciences, 2010, 53 (8): 2261–2271.
 Wei Z H, Yuan L L, Liu B D, et al. A micro-CL system and its applications [J]. Review of Scientific Instruments, 2017, 88 (11): 115107.
 Que J M, Cao D Q, Zhao W, et al. Computed laminography and reconstruction algorithm [J]. Chinese Physics C, 2012, 36 (8): 777–783.
 Kak A C, Slaney M, Wang G. Principles of computerized tomographic imaging [J]. Medical Physics, 2002, 29 (1): 107–107.
 Ye Y B, Wang G. Filtered backprojection formula for exact image reconstruction from cone-beam data along ageneral scanning curve [J]. Medical Physics, 2005, 32 (1): 42–48.
 Wu W W, Yu H Y, Cong W X, et al. Theoretically exact backprojection filtration algorithm for multisegment linear trajectory [J]. Physics in Medicine & Biology, 2018, 63 (1): 015037.
 Ma C X, Hu J J, Yan B. Optimization of fan-beam CT filtered backprojection reconstruction algorithm [J]. Laser & Optoelectronics Progress, 2012, 49 (9): 091103(in Chinese).
 Liu F L, Yu H Y, Cong W X, et al. Top-level design and pilot analysis of low-end CT scanners based on linear scanning for developing countries [J]. Journal of X-Ray Science and Technology, 2014, 22 (5): 673–686.
 Wu W W, Yu H Y, Wang S Y, et al. BPF-type region-of-interest reconstruction for parallel translational computed tomography [J]. Journal of XRay Science and Technology, 2017, 25 (3): 487–504.
 Wu W W, Quan C, Liu F L. Filtered back-projection image reconstruction algorithm for opposite parallel linear CT scanning [J]. Acta Optica Sinica, 2016, 36 (9): 0911009 (in Chinese).
 Gao H X, Luo L, Luo Y H, et al. Improved stochastic CT reconstruction based on particle swarm optimization for limited-angle sparse projection data [J]. Acta Optica Sinica, 2018, 38 (1): 0111003 (in Chinese).
 Gordon R, Bender R, Herman G T. Algebraic Reconstruction Techniques (ART) for three-dimensional electron microscopy and X-ray photography [J]. Journal of Theoretical Biology, 1970, 29 (3): 471–481.
 Andersen A H, Kak A C. Simultaneous algebraic reconstruction technique (SART): a superior implementation of the art algorithm [J]. Ultrasonic Imaging, 1984, 6 (1): 81–94.
 Yu H Y, Wang G. Compressed sensing based interior tomography [J]. Physics in Medicine and Biology, 2009, 54 (9): 2791–2805.
 Lu X. Limited angle computed tomography recontruction algorithm based on multiplicative regularization method [J]. Acta Optica Sinica, 2010, 30 (5): 1285–1290 (in Chinese).
 Gao Y, Yun L J, Shi J S, et al. Enhancement dark channel algorithm of fog image based on the TV model [J]. Chinese Journal of Lasers, 2015, 42 (8): 0809001 (in Chinese).
 Wu W W, Yu H Y, Gong C C, et al. Swinging multi-source industrial CT systems for aperiodic dynamic imaging [J]. Optics Express, 2017, 25 (20): 24215–24235.