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Optics Express

Optics Express

  • Editor: Andrew M. Weiner
  • Vol. 21, Iss. 23 — Nov. 18, 2013
  • pp: 27946–27963

An approach to increasing the resolution of industrial CT images based on an aperture collimator

Yining Zhu, Defeng Chen, Yunsong Zhao, Hongwei Li, and Peng Zhang  »View Author Affiliations

Optics Express, Vol. 21, Issue 23, pp. 27946-27963 (2013)

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The spatial resolution of CT images is dominated by the focal spot size when it is large relative to the detector cells. We propose an approach to increase the spatial resolution by utilizing an aperture collimator. The aperture collimator is specially designed and placed in front of the X-ray source so that the rays penetrating the collimator form a set of narrow fan beams. Then an iterative algorithm is introduced to reconstruct CT images from the data obtained by scanning the narrow fan beams. Numerical experiments show that the proposed approach could significantly increase the resolution of the CT images. Furthermore, this approach is also robust against some challenging cases, such as the examination of low contrast object, reconstruction based on multi-energy data and perturbation of geometric errors in CT systems.

© 2013 OSA

OCIS Codes
(170.7440) Medical optics and biotechnology : X-ray imaging
(340.7430) X-ray optics : X-ray coded apertures

ToC Category:
Medical Optics and Biotechnology

Original Manuscript: April 16, 2013
Revised Manuscript: September 20, 2013
Manuscript Accepted: October 23, 2013
Published: November 7, 2013

Virtual Issues
Vol. 9, Iss. 1 Virtual Journal for Biomedical Optics

Yining Zhu, Defeng Chen, Yunsong Zhao, Hongwei Li, and Peng Zhang, "An approach to increasing the resolution of industrial CT images based on an aperture collimator," Opt. Express 21, 27946-27963 (2013)

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  1. H.  Hu, “Multi-slice helical CT: scan and reconstruction,” Medical Physics 26, 5–18 (1999). [CrossRef] [PubMed]
  2. J.  Hsieh, Computed Tomography: Principles, Design, Artifacts, and Recent Advances (SPIE Press, 2003, vol. PM188).
  3. H.  Zhang, J.  Tian, M.  Chen, P.  Zhang, “A novel scanning mode and image reconstruction method on super-resolution CT,” Chin. J. Stereol. Image Analysis 9, 154–157 (2005).
  4. T.M.  Peters, R.M.  Lewitt, “Computed tomography with fan-beam geometry,” J. Comput. Assist. Tomogr. 1, 429–436 (1977). [CrossRef] [PubMed]
  5. A. H.  Lonn, “Computed tomography system with translatable focal spot,” US Patent 45, 5173852 (1990).
  6. J.  Hsieh, M.F.  Gard, S.  Gravelle, “Reconstruction technique for focal spot wobbling,”Proc. of SPIE Medical Imaging VI 1652, 175–182 (1992). [CrossRef]
  7. E.  Caroli, J. B.  Stephen, G.  Cocco, L.  Natalucci, A.  Spizzichino, “Coded aperture imaging in x- and gamma-ray astronomy,” Space Sci. Rev. 45, 349–403 (1987). [CrossRef]
  8. T.  Palmieri, “Multiplex methods and advantages in x-ray astronomy,” Astrophys. Space Sci. 28, 277–287 (1974). [CrossRef]
  9. P.  Durouchoux, H.  Hudson, J.  Matteson, G.  Hurford, K.  Hurley, E.  Orsal, “Gamma-ray imaging with a rotating modulator,” Astron. Astrophys. 120, 150–155 (1983).
  10. G.  Skinner, “Imaging with coded-aperture masks,” Nucl. Instr. Meth. Phys. Res. 221, 33–40 (1984). [CrossRef]
  11. S.  Webb, The Physics of Medical Imaging (Taylor & Francis, 2010).
  12. G.  Knoll, W.  Rogers, K.  Koral, J.  Stamos, N.  Clinthorne, “Application of coded apertures in tomographic head scanning,” Nucl. Instr. Meth. Phys. Res. 221, 226–232 (1984). [CrossRef]
  13. W. E.  Smith, R. G.  Paxman, H. H.  Barrett, “Image reconstruction from coded data: I. reconstruction algorithms and experimental results.” J. Opt. Soc. Am. A 2, 491–500 (1985). [CrossRef] [PubMed]
  14. R.  Accorsi, F.  Gasparini, R. C.  Lanza, “A coded aperture for high-resolution nuclear medicine planar imaging with a conventional anger camera: experimental results,” IEEE Trans. Nucl. Sci. 48, 2411–2417 (2001). [CrossRef]
  15. Z.  Mu, Y.-H.  Liu, “Aperture collimation correction and maximum-likelihood image reconstruction for near-field coded aperture imaging of single photon emission computerized tomography,” IEEE Trans. Medical Imaging 25, 701–711 (2006). [CrossRef]
  16. R. J.  Jaszczak, J.  Li, H.  Wang, M. R.  Zalutsky, R. E.  Coleman, “Pinhole collimation for ultra-high-resolution, small-field-of-view SPECT.” Phys. Med. Biol. 39, 425–437 (1994). [CrossRef] [PubMed]
  17. K.  Ogawa, T.  Kawade, K.  Nakamura, A.  Kubo, T.  Ichihara, “Ultra high resolution pinhole spect for small animal study,” IEEE Trans. Nucl. Sci. 45, 3122–3126 (1998). [CrossRef]
  18. T.  Zeniya, H.  Watabe, T.  Aoi, K. M.  Kim, N.  Teramoto, T.  Hayashi, A.  Sohlberg, H.  Kudo, H.  Iida, “A new reconstruction strategy for image improvement in pinhole SPECT.” Eur. J. Nucl. Med. Mol. Imaging 31, 1166–1172 (2004). [CrossRef] [PubMed]
  19. S. D.  Metzler, J. E.  Bowsher, M. F.  Smith, R. J.  Jaszczak, “Analytic determination of pinhole collimator sensitivity with penetration,” IEEE Trans. Medical Imaging 20, 730–741 (2001). [CrossRef]
  20. E. E.  Fenimore, T. M.  Cannon, “Uniformly redundant arrays: digital reconstruction methods.” Appl. Opt. 20, 1858–1864 (1981). [CrossRef] [PubMed]
  21. A.  Olivo, R.  Speller, “A coded-aperture technique allowing x-ray phase contrast imaging with conventional sources,” Appl. Phys. Lett. 91, 074106 (2007). [CrossRef]
  22. D. J.  Brady, N. P.  Pitsianis, X.  Sun, “Reference structure tomography,” JOSA. A. 21, 1140–1147 (2004). [CrossRef] [PubMed]
  23. K.  Choi, D. J.  Brady, “Coded aperture computed tomography,” Proc. of SPIE 74680B, 1–4 (2009).
  24. J.  Fleming, B.  Goddard, “An evaluation of techniques for stationary coded aperture three-dimensional imaging in nuclear medicine,” Nucl. Instr. Meth. Phys. Res. 221, 242–246 (1984). [CrossRef]
  25. J. H.  Hubbell, S. M.  Seltzer, “Tables of x-ray mass attenuation coefficients and mass energy-absorption coefficients from 1 kev to 20 mev for elements z = 1 to 92 and 48 additional substances of dosimetric interest,” http://www.nist.gov/pml/data/xraycoef/ .
  26. A. C.  Kak, M.  Slaney, Principles of Tomographic Imaging (IEEE Engineering in Medicine and Biology Society, 2001). [CrossRef]
  27. G.  Lauritsch, H.  Bruder, “Head phantom,” http://www.imp.uni-erlangen.de/phantoms/head (2012).

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