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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
Article

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 

Notes

Acknowledgments

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.

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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

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