工业CT技术研究——提高CT图像质量的几个途径
摘要
随着航空航天、兵器、汽车等工业的发展，对其关键部件的检测提出了更
高的要求。工业计算机层析技术（ICT）是一种先进的无损检测技术。具有无
损、无接触、高分辨率等优点，被国际无损检测技术界称为最佳无损检测手段。
讨论了从投影预处理到图像重建的整个CT过程。比较了重建算法中滤波
器长度对重建结果的影响。用面阵CT可重建任意截面切片图像。根据投影的
空间频谱选用巴特沃斯窗对投影滤波，得到了满意的结果。分析了CT图像伪
迹的一些表现及产生机理。对于截断式CT，给出了几种实用的重建方法。
With the developments of aerospace,ordnance and automobile industries, it is
imperative to inspect their vital components. Industrial Compaterized TomograPhy
(lCT) is one of the advanced means for NDT which has the virtUres of non-
destructive, non-contact and high resolution. It is called the best means for NDT by
the circle of international NDT technology.
The whole process of ICT is discussed from pretreat to image reconstruction. As
for the influence on the image quality different filter lengths are compared. Using
CCD matrix as detectoF, arbitrary s1ices can be reconstructed. According to the
spatial spectrum of projections, a Butterworth window is used to filtrate the
prOjections and desirabIe images are obtained. Several sorts of artifacts on CT image
are analysed and their causes are investigated. To reconstruct images from
trunctuated projections, some feasible methods are developed,
高的要求。工业计算机层析技术（ICT）是一种先进的无损检测技术。具有无
损、无接触、高分辨率等优点，被国际无损检测技术界称为最佳无损检测手段。
讨论了从投影预处理到图像重建的整个CT过程。比较了重建算法中滤波
器长度对重建结果的影响。用面阵CT可重建任意截面切片图像。根据投影的
空间频谱选用巴特沃斯窗对投影滤波，得到了满意的结果。分析了CT图像伪
迹的一些表现及产生机理。对于截断式CT，给出了几种实用的重建方法。
With the developments of aerospace,ordnance and automobile industries, it is
imperative to inspect their vital components. Industrial Compaterized TomograPhy
(lCT) is one of the advanced means for NDT which has the virtUres of non-
destructive, non-contact and high resolution. It is called the best means for NDT by
the circle of international NDT technology.
The whole process of ICT is discussed from pretreat to image reconstruction. As
for the influence on the image quality different filter lengths are compared. Using
CCD matrix as detectoF, arbitrary s1ices can be reconstructed. According to the
spatial spectrum of projections, a Butterworth window is used to filtrate the
prOjections and desirabIe images are obtained. Several sorts of artifacts on CT image
are analysed and their causes are investigated. To reconstruct images from
trunctuated projections, some feasible methods are developed,
引文
[1]Tonner Pahl. D, Stanley..J.H., Mater Eval, 1992;1434-1438
[2]Takahiro KANAMORI, ShouJI KAMATA, Cross-sectional imaging of large and dense materials by high energy X-ray CT using linear accelerator, Journal of Nuclear Science and Technology, 26(9), September, 1989
[3]郭志平，董宇峰，张朝宗 工业CT技术：工业CT技术发展概况 无损检测 1996．1
[4]刘德镇，现代射线检测技术，中国标准出版社，p250-252，1999．8，
[5]中国机械工程学会无损检测分会编，射线检测技术，机械工业出版社．pp144-145．1996．12
[6]J.Radon,Math. Phys,PP262-277,1917
[7]Cormak A M.Representation of a function by ites line integrates with some radiological applications.Journal of Applied Physics,34(9)
[8]G.N.Hounsfield,Computerized transverse axial scanning(tomography):part I Description of system. British Journal of Radiology,46:1016-1022
[9]G.T.Herman,Image reconstruction from projections. The fundamentals of computerized tomography. New York:Academic Press, 1980.
[10]L. A. Feldkamp, L .C. Davis, J .W. Kress. Proctical cone beam algorithms. Journal of Optical Soc.Am.A,vol. 1,pp.612-619,1984.
[11] H. K. Tuy,An inversion formula for cone-beam reconstruction.SIAM J.Appl. Math.,vol.43,pp546-552,1983.
[12]B.D. Smith. Image Reconstruction from Cone-Beam Projections:Necessary and Sufficient Conditions and Reconstruction Methods. IEEE Transactions on medical imaging, vol. 4,pp14-25,1985.
[13]B.D. Smith. Cone-beam tomography:recent advances and tutorial review. Optical Engineering,vol. 29,pp524-534,1990.
[14]B.D. Smith, J. Chen, Implementation,Inverstigation,and Improvement of a Novel Cone-Beam Reconstruction Method. IEEE Transactions on medical imaging, vol. 11,pp260-266,1992..
[15]P. Grangeat, P. Lemasson,P. Melennec,and P. Sire, Evaluation of the 3-D Radon transform algorithm for cone-beam reconstruction, SPIE 1445,pp320-331,1991.
[16]M. Defrise ,R. Clack. A cone-beam reconstruction algorithm using shift-invariant filtering and cone-beam backprojection. IEEE Transactions on Medical Imaging, vol 13,pp 186-195,1994.
[17]H. Hudo, T. Saito, Derivation and implementation of a cone-beam reconstruction algorithm for non-plannar oribits. IEEE Transactions on Medical Imaging,vol 13. No. 1,pp 196-211,1994.
[18]毛希平，三维锥束CT精确图象重建的理论与方法研究，清华大学博士论文，1997．
[19]K. C. Tam, S. Samarasekera and F. Sauer, Exact cone beam CT with a spiral scan, Phys. Med. Biol.vol 43,pp 1015-1024,1998.
[20]高上凯，医学成像系统，清华大学出版社，pp44-46，2000．3．
[21]周光湖，计算机断层摄影原理及应用，成都电讯工程学院，p75，1986．
[22]庄天戈，CT原理与算法，上海交通大学出版社，1992
[23]高得琦，锥形束卷积三维CT图象重建方法的实现与实物分析研究，清华大学硕士论文，pp14-15．
[24]M. Defrise,Clack R Overview of reconstruction algorithms for excat cone-beam tomography, SPIE Vol.2299, p233.
[25]杨民，与转轴任意相交角下的CT改进算法——预处理、校正与滤波卷积反投影．华北工学院硕士论文．pp29-37．2000．
[26]唐荣锡等，计算机图形学教程，科学出版社，pp197-198，1991．
[27]张朝宗等，用几何参数表方法实现快速重建CT图象，清华大学学报Vol 38，pp47-49．
[28]G.T.Herman等著，谢宗钧等译，投影法图像重建—实现和应用．国防工业出版社，pp21-23,pp74-75．1992．
[29]吕军震，张朝宗，郭志平．微焦点X-CT系统的伪像研究及滤波函数分析．第八届全国核电子学与核探测技术学术年会论文集，pp453-456，1991．
[30]Graham R. Davis, Image quality in X-ray microtomography, SPIE Vol.3149,p218.
[31]O. Demirkaya, E. L.Ritman, Noise reduction in x-ray microtographyic images by anisotropic diffusion of the scanner projection images. SPIE Vol.3661, pp690-697, 1999.
[32]Amit Sawant,Herbert Zeman An adaptive median filter algorithm to remove inpulse noise in x- ray and CT images and speckle in ultrasound images, SPIE Vol.3661, pp
[33]Jiang Hsieh, Reconstruction bias resulting from weighted projection and iso-center misalignment, SPIE Vol.3661,pp442-449.
[34]王召巴，旋转中心偏移对CT重建图像质量的影响，兵工学报，已收录．
[2]Takahiro KANAMORI, ShouJI KAMATA, Cross-sectional imaging of large and dense materials by high energy X-ray CT using linear accelerator, Journal of Nuclear Science and Technology, 26(9), September, 1989
[3]郭志平，董宇峰，张朝宗 工业CT技术：工业CT技术发展概况 无损检测 1996．1
[4]刘德镇，现代射线检测技术，中国标准出版社，p250-252，1999．8，
[5]中国机械工程学会无损检测分会编，射线检测技术，机械工业出版社．pp144-145．1996．12
[6]J.Radon,Math. Phys,PP262-277,1917
[7]Cormak A M.Representation of a function by ites line integrates with some radiological applications.Journal of Applied Physics,34(9)
[8]G.N.Hounsfield,Computerized transverse axial scanning(tomography):part I Description of system. British Journal of Radiology,46:1016-1022
[9]G.T.Herman,Image reconstruction from projections. The fundamentals of computerized tomography. New York:Academic Press, 1980.
[10]L. A. Feldkamp, L .C. Davis, J .W. Kress. Proctical cone beam algorithms. Journal of Optical Soc.Am.A,vol. 1,pp.612-619,1984.
[11] H. K. Tuy,An inversion formula for cone-beam reconstruction.SIAM J.Appl. Math.,vol.43,pp546-552,1983.
[12]B.D. Smith. Image Reconstruction from Cone-Beam Projections:Necessary and Sufficient Conditions and Reconstruction Methods. IEEE Transactions on medical imaging, vol. 4,pp14-25,1985.
[13]B.D. Smith. Cone-beam tomography:recent advances and tutorial review. Optical Engineering,vol. 29,pp524-534,1990.
[14]B.D. Smith, J. Chen, Implementation,Inverstigation,and Improvement of a Novel Cone-Beam Reconstruction Method. IEEE Transactions on medical imaging, vol. 11,pp260-266,1992..
[15]P. Grangeat, P. Lemasson,P. Melennec,and P. Sire, Evaluation of the 3-D Radon transform algorithm for cone-beam reconstruction, SPIE 1445,pp320-331,1991.
[16]M. Defrise ,R. Clack. A cone-beam reconstruction algorithm using shift-invariant filtering and cone-beam backprojection. IEEE Transactions on Medical Imaging, vol 13,pp 186-195,1994.
[17]H. Hudo, T. Saito, Derivation and implementation of a cone-beam reconstruction algorithm for non-plannar oribits. IEEE Transactions on Medical Imaging,vol 13. No. 1,pp 196-211,1994.
[18]毛希平，三维锥束CT精确图象重建的理论与方法研究，清华大学博士论文，1997．
[19]K. C. Tam, S. Samarasekera and F. Sauer, Exact cone beam CT with a spiral scan, Phys. Med. Biol.vol 43,pp 1015-1024,1998.
[20]高上凯，医学成像系统，清华大学出版社，pp44-46，2000．3．
[21]周光湖，计算机断层摄影原理及应用，成都电讯工程学院，p75，1986．
[22]庄天戈，CT原理与算法，上海交通大学出版社，1992
[23]高得琦，锥形束卷积三维CT图象重建方法的实现与实物分析研究，清华大学硕士论文，pp14-15．
[24]M. Defrise,Clack R Overview of reconstruction algorithms for excat cone-beam tomography, SPIE Vol.2299, p233.
[25]杨民，与转轴任意相交角下的CT改进算法——预处理、校正与滤波卷积反投影．华北工学院硕士论文．pp29-37．2000．
[26]唐荣锡等，计算机图形学教程，科学出版社，pp197-198，1991．
[27]张朝宗等，用几何参数表方法实现快速重建CT图象，清华大学学报Vol 38，pp47-49．
[28]G.T.Herman等著，谢宗钧等译，投影法图像重建—实现和应用．国防工业出版社，pp21-23,pp74-75．1992．
[29]吕军震，张朝宗，郭志平．微焦点X-CT系统的伪像研究及滤波函数分析．第八届全国核电子学与核探测技术学术年会论文集，pp453-456，1991．
[30]Graham R. Davis, Image quality in X-ray microtomography, SPIE Vol.3149,p218.
[31]O. Demirkaya, E. L.Ritman, Noise reduction in x-ray microtographyic images by anisotropic diffusion of the scanner projection images. SPIE Vol.3661, pp690-697, 1999.
[32]Amit Sawant,Herbert Zeman An adaptive median filter algorithm to remove inpulse noise in x- ray and CT images and speckle in ultrasound images, SPIE Vol.3661, pp
[33]Jiang Hsieh, Reconstruction bias resulting from weighted projection and iso-center misalignment, SPIE Vol.3661,pp442-449.
[34]王召巴，旋转中心偏移对CT重建图像质量的影响，兵工学报，已收录．