DOI QR코드

DOI QR Code

APPLICATION OF A DUAL-ENERGY MONOCHROMATIC XRAY CT ALGORITHM TO POLYCHROMATIC X-RAY CT: A FEASIBILITY STUDY

  • Chang, S. (Department of Nuclear Quantum Engineering, Korea Advanced Institute of Science and Technology) ;
  • Lee, H.K. (Department of Mining and Nuclear Engineering, Missouri University of Science and Technology) ;
  • Cho, G. (Department of Nuclear Quantum Engineering, Korea Advanced Institute of Science and Technology)
  • Received : 2010.08.23
  • Accepted : 2011.06.06
  • Published : 2012.02.25

Abstract

In this study, a simple post-reconstruction dual-energy computed tomography (CT) method is proposed. A dual-energy CT algorithm for monochromatic x-rays was adopted and applied to the dual-energy CT of polychromatic x-rays by assigning a representative mono-energy. The accuracy of algorithm implementation was tested with mathematical phantoms. To test the sensitivity of this algorithm to the inaccuracy of representative energy value in energy values, a simulation study was performed with mathematical phantom. To represent a polychromatic x-ray energy spectrum with a single-energy, mean energy and equivalent energy were used, and the results were compared. The feasibility of the proposed method was experimentally tested with two different micro-CTs and a test phantom made of polymethyl methacrylate (PMMA), water, and graphite. The dual-energy calculations were carried out with CT images of all possible energy pairs among 40, 50, 60, 70, and 80 kVp. The effective atomic number and the electron density values obtained from the proposed method were compared with theoretical values. The results showed that, except the errors in the effective atomic number of graphite, most of the errors were less than 10 % for both CT scanners, and for the combination of 60 kVp and 70 kVp, errors less than 6.0 % could be achieved with a Polaris 90 CT. The proposed method shows simplicity of calibration, demonstrating its practicality and feasibility for use with a general polychromatic CT.

Keywords

References

  1. R. E. Alvarez, and A. Macovski, "Energy-selective reconstructions in X-ray computerized tomography," Phys Med Biol, vol. 21, no. 5, pp. 733-44, Sep, 1976. https://doi.org/10.1088/0031-9155/21/5/002
  2. T. R. Johnson, B. Krauss, M. Sedlmair et al., "Material differentiation by dual energy CT: initial experience," Eur Radiol, vol. 17, no. 6, pp. 1510-7, Jun, 2007. https://doi.org/10.1007/s00330-006-0517-6
  3. A. J. Coleman, and M. Sinclair, "A beam-hardening correction using dual-energy computed tomography," Phys Med Biol, vol. 30, no. 11, pp. 1251-6, Nov, 1985. https://doi.org/10.1088/0031-9155/30/11/007
  4. E. Y. Sidky, Y. Zou, and X. Pan, "Impact of polychromatic x-ray sources on helical, cone-beam computed tomography and dual-energy methods," Phys Med Biol, vol. 49, no. 11, pp. 2293-303, Jun 7, 2004. https://doi.org/10.1088/0031-9155/49/11/012
  5. M. J. Guy, "DETECT - Dual energy transmission estimation CT - for improved attenuation correction in SPECT and PET," IEEE Transactions on Nuclear Science, vol. 45, no. 3 PART 2, pp. 1261-1267, 1998. https://doi.org/10.1109/23.682013
  6. P. E. Kinahan, A. M. Alessio, and J. A. Fessler, "Dual energy CT attenuation correction methods for quantitative assessment of response to cancer therapy with PET/CT imaging," Technol Cancer Res Treat, vol. 5, no. 4, pp. 319-27, Aug, 2006. https://doi.org/10.1177/153303460600500403
  7. Z. Ying, R. Naidu, and C. R. Crawford, "Dual energy computed tomography for explosive detection," Journal of X-Ray Science and Technology, vol. 14, no. 4, pp. 235- 256, 2006.
  8. Z. Ying, R. Naidu, K. Guilbert et al., "Dual energy volumetric X-ray tomographic sensor for luggage screening."
  9. L. A. Lehmann, R. E. Alvarez, A. Macovski et al., "Generalized image combinations in dual KVP digital radiography," Med Phys, vol. 8, no. 5, pp. 659-67, Sep- Oct, 1981. https://doi.org/10.1118/1.595025
  10. K. S. Chuang, and H. K. Huang, "A fast dual-energy computational method using isotransmission lines and table lookup," Med Phys, vol. 14, no. 2, pp. 186-92, Mar-Apr, 1987. https://doi.org/10.1118/1.596110
  11. G. Zhang, Z. Chen, L. Zhang et al., "Exact Reconstruction for Dual Energy Computed Tomography Using an H-L Curve Method." pp. 3485 - 3488.
  12. G. Christ, "Exact treatment of the dual-energy method in CT using polyenergetic X-ray spectra," Phys Med Biol, vol. 29, no. 12, pp. 1501-10, Dec, 1984. https://doi.org/10.1088/0031-9155/29/12/005
  13. J. C. Steenbeek, C. van Kuijk, J. L. Grashuis et al., "Selection of fat-equivalent materials in postprocessing dual-energy quantitative CT," Med Phys, vol. 19, no. 4, pp. 1051-6, Jul-Aug, 1992. https://doi.org/10.1118/1.596823
  14. M. M. Goodsitt, and R. H. Johnson, "Precision in quantitative CT: impact of x-ray dose and matrix size," Med Phys, vol. 19, no. 4, pp. 1025-36, Jul-Aug, 1992. https://doi.org/10.1118/1.596820
  15. M. M. Goodsitt, "Beam hardening errors in post-processing dual energy quantitative computed tomography," Med Phys, vol. 22, no. 7, pp. 1039-47, Jul, 1995. https://doi.org/10.1118/1.597590
  16. B. J. Heismann, J. Leppert, and K. Stierstorfer, "Density and atomic number measurements with spectral x-ray attenuation method," Journal of Applied Physics, vol. 94, no. 3, pp. 2073-2079, 2003. https://doi.org/10.1063/1.1586963
  17. P. Sukovic, and N. H. Clinthorne, "Penalized weighted least-squares image reconstruction for dual energy X-ray transmission tomography," IEEE Trans Med Imaging, vol. 19, no. 11, pp. 1075-81, Nov, 2000. https://doi.org/10.1109/42.896783
  18. B. De Man, J. Nuyts, P. Dupont et al., "An iterative maximum-likelihood polychromatic algorithm for CT," IEEE Trans Med Imaging, vol. 20, no. 10, pp. 999-1008, Oct, 2001. https://doi.org/10.1109/42.959297
  19. J. A. Fessler, I. Elbakri, P. Sukovic et al., "Maximumlikelihood dual-energy tomographic image reconstruction." pp. 38-49.
  20. M. Torikoshi, T. Tsunoo, M. Sasaki et al., "Electron density measurement with dual-energy x-ray CT using synchrotron radiation," Phys Med Biol, vol. 48, no. 5, pp. 673-85, Mar 7, 2003. https://doi.org/10.1088/0031-9155/48/5/308
  21. M. Torikoshi, T. Tsunoo, Y. Ohno et al., "Features of dual-energy X-ray computed tomography," Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 548, no. 1-2, pp. 99-105, 2005. https://doi.org/10.1016/j.nima.2005.03.074
  22. C. Rizescu, C. Besöliu, and A. Jipa, "Determination of local density and effective atomic number by the dualenergy computerized tomography method with the 192Ir radioisotope," Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 465, no. 2-3, pp. 584-599, 2001. https://doi.org/10.1016/S0168-9002(01)00181-4
  23. H. J. Vinegar, and S. L. Wellington, Method of imaging the atomic number of a sample, US, 1986.
  24. F. Kelcz, P. M. Joseph, and S. K. Hilal, "Noise considerations in dual energy CT scanning," Med Phys, vol. 6, no. 5, pp. 418-25, Sep-Oct, 1979. https://doi.org/10.1118/1.594520
  25. G. Poludniowski, G. Landry, F. DeBlois et al., "SpekCalc: a program to calculate photon spectra from tungsten anode x-ray tubes," Phys Med Biol, vol. 54, no. 19, pp. N433-8, Oct 7, 2009. https://doi.org/10.1088/0031-9155/54/19/N01

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