Journal of Digital Imaging

, Volume 19, Issue 4, pp 351–361 | Cite as

A Study of Grid Artifacts Formation and Elimination in Computed Radiographic Images

  • Chih-Yang Lin
  • Wen-Jeng Lee
  • Shyh-Jye Chen
  • Ching-Hwa Tsai
  • Jei-Han Lee
  • Chia-Hung Chang
  • Yu-Tai ChingEmail author

Computed radiography (CR) has many advantages such as filmless operations, efficiency, and convenience. Furthermore, it is easier to integrate with the picture archiving and communication systems. Another important advantage is that CR images generally have a wider dynamic range than conventional screen film. Unfortunately, grid artifacts and moiré pattern artifacts may be present in CR images. These artifacts become a more serious problem when viewing CR images on a computer monitor when a clinic grade monitor is not available. Images produced using a grid with higher frequency or a Potter–Bucky grid (i.e., a moving grid, Bucky for short) can reduce occurrence but cannot guarantee elimination of these artifacts [CR & PACS (2000); Detrick F (2001), pp 7–8]. In this paper, the formation of the artifacts is studied. We show that the grid artifacts occur in a narrow band of frequency in the frequency domain. The frequency can be determined, accurately located, and thus removed from the frequency domain. When comparing the results obtained from the proposed method against the results obtained using previous computer methods, we show that our method can achieve better image quality.

Key Words

Moiré aliasing computed radiography grid Bucky 



This work was supported under the grants NSC-90-2213-E-009-119, National Science Council, Taiwan, and 91-S009 from the National Taiwan University Hospital, Taipei, Taiwan.


  1. 1.
    Cesar LJ, Schueler BA, Zink FE, Daly TR, Taubel JP, Jorgenson LL: Artifacts found in computed radiography. Br J Radiol 195-202, 2001Google Scholar
  2. 2.
    Lee Wen-jeng, Tsao Bo-Shen, Ching Yu-Tai, Chen Shyh-Jye, Chang Chia-Hung, Chen Chien-Jung, Yen York, Lee Yuan-Ten: High Resolution Hand-held computer as a Portable PACS Terminal Using Wireless LAN and GPRS. EuroPACS 2002 Conference, Oulu, FinlandGoogle Scholar
  3. 3.
    Wang Jun, Huang HK: Film digitization aliasing artifacts caused by grid line patterns. IEEE Trans Med Imaging 375–385, 1994Google Scholar
  4. 4.
    Barski LL, Wang X: Characterization, detection and suppression of stationary grids in digital projection radiography imagery. Proc SPIE 502-519, 1999Google Scholar
  5. 5.
    Belykh IN, Cornelius CW: Antiscatter stationary grid artifacts automated detection and removal in projection radiography images. Proc SPIE 1162–1166, 2001Google Scholar
  6. 6.
    Sasada R, Yamada M, Hara S, Takeo H: Stationary grid pattern removal using 2-dimensional technique for Moire-free radiographic image display. Proc SPIE, 2003Google Scholar
  7. 7.
    Castlenman KR: Digital Image Process. Upper Saddle River, NJ: Prentice Hall International Editions, p. 41, 1996Google Scholar
  8. 8.
    Beutel, JKundel, HLMetter, RLV eds. 2000Handbook of Medical Imaging: Physics and PsychophysicsSPIE PressBellingham, WAGoogle Scholar
  9. 9.
    Bushberg, JT 2002The essential physics of medical imaging2nd ed.Lippincott Williams & WilkinsBaltimore, MDGoogle Scholar
  10. 10.
    Rowlands JA: The physics of computed radiography. Phys Med Biol 123-166, 2002Google Scholar
  11. 11.
    Ganten M, Radeleff B, Kampschulte A, Daniels MD, Kauffmann GW, Hansmann J: Comparing image quality of flat-panel chest radiography with storage phosphor radiography and film-screen radiography. Am Roentgen Ray Soc 171-176, 2003Google Scholar
  12. 12.
    Chaefer-Prokop C, Uffmann M, Eisenhuber E, Prokop M: Digital radiography of the chest: detector performance parameters. J Thorac Imaging 124-137, 2003Google Scholar
  13. 13.
    Harrell G, Chotas T. James, Dobbins E. Carl, Ravin: Principles of digital radiography with large-area, electronically readable detectors: a review of the basics. Rev Princ Digit Radiogr 595-599, 1999Google Scholar
  14. 14.
    Cadzow, JA, Landingham, HF 1974Signals, Systems, and TransformPrentice-HallEnglewood Cliffs, New YorkGoogle Scholar
  15. 15.
    Linden DA: A discussion of sampling theorems. Proc. IRE 1219-1226, 1959Google Scholar
  16. 16.
    Goodman, JW 1968Introduction to Fourier OpticsMcGraw-HillNew YorkGoogle Scholar
  17. 17.
    Kafri, O, Glatt, I 1990Topography and Spinal DeformityWileyNew YorkGoogle Scholar
  18. 18.
    Lia M, Wilsona D, Wonga M, Xthona A: The evolution of display technologies in PACS applications. Comput Med Imaging Graph 175-184, 2003Google Scholar
  19. 19.
    CR & PACS: Insights & Images—Grids for Computed Radiography. The User’s Publication of Computed Radiography, Fall 2000Google Scholar
  20. 20.
    Detrick F: PACS Planning Guide. Air Force Medical Logistics Office/FOE, Technology Integration and Support Team, pp 7-8, 2001Google Scholar
  21. 21.
    DICOM Standard: Digital Imaging and Communications in Medicine (DICOM) Part 3: Information Object Definitions. National Electrical Manufacturers Association, 2004Google Scholar
  22. 22.
    Fujifilm Standard: DICOM Conformance Statement Fuji Computed Radiography QA-WS771. Fuji Photo Film Co. Ltd, Japan, 2001Google Scholar
  23. 23.
    AGFA: Healthcare DICOM Conformance Statement: ADC-QS Version 2.1. HealthCare Glasgow Business Community, Sep., 2002Google Scholar
  24. 24.
    Bushong SC: Physics, Biology, and Protection. Radiologic Science for Technologists,” 7th ed. 2001Google Scholar

Copyright information

© SCAR (Society for Computer Applications in Radiology) 2006

Authors and Affiliations

  • Chih-Yang Lin
    • 1
  • Wen-Jeng Lee
    • 2
  • Shyh-Jye Chen
    • 2
  • Ching-Hwa Tsai
    • 2
  • Jei-Han Lee
    • 1
  • Chia-Hung Chang
    • 2
  • Yu-Tai Ching
    • 1
    Email author
  1. 1.Department of Computer and Information ScienceNational Chiao Tung UniversityHsin ChuRepublic of China
  2. 2.Department of Medical ImagingNational Taiwan University HospitalTaipeiRepublic of China

Personalised recommendations