Journal of radiological science and technology (대한방사선기술학회지:방사선기술과학)

Korean Society of Radiological Science (대한방사선과학회)
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Investigation of Physical Imaging Properties in Various Digital Radiography Systems

다양한 디지털 방사선 시스템의 물리적 영상 특성 조사

  • Jeong, Hoi-Woun (Department of Radiological Science, Baekseok Culture University) ;
  • Min, Jung-Hwan (Department of Radiological technology, Shingu University) ;
  • Yoon, Yong-Su (Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University) ;
  • Kim, Jung-Min (Department of Health and Environmental Science, College of Health Science, Korea University)
  • 정회원 (백석문화대학교 방사선과) ;
  • 민정환 (신구대학교 방사선과) ;
  • 윤용수 (규슈대학교 의학계학부 보건학전공) ;
  • 김정민 (고려대학교 보건과학대학 보건환경융합과학부)
  • Received : 2017.08.03
  • Accepted : 2017.09.13
  • Published : 2017.09.30
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Abstract

We aimed to evaluate the physical imaging properties in various digital radiography systems with charged coupled device (CCD), computed radiography (CR), and indirect flat panel detector (FPD). The imaging properties measured in this study were modulation transfer function (MTF) wiener spectrum (WS), and detective quantum efficiency (DQE) to compare the performance of each digital radiography system. The system response of CCD were in a linear relationship with exposure and that of CR and FPD were proportional to the logarithm of exposure. The MTF of both CR and FPD indicated a similar tendency but in case of CCD, it showed lower MTF than that of CR and FPD. FPD showed the lowest WS and also indicated the highest DQE among three systems. According to the results, digital radiography system with different type of image receptor had its own image characteristics. Therefore, it is important to know the physical imaging characteristics of the digital radiography system accurately　to obtain proper image quality.

본 연구는 전하결합소자(charged coupled device; CCD), CR (computed radiography), 평판형검출기(flat panel detector; FPD) 등을 사용하는 다양한 디지털 방사선(digital radiography; DR) 시스템의 물리적 영상 특성의 평가를 실시한 것이다. 본 연구에서 적용된 영상 특성은 신호응답특성(system response), 해상력특성(modulation transfer function; MTF), 잡음특성(wiener spectrum; WS), 양자검출효율(detective quantum efficiency; DQE) 등이며 이를 통하여 DR 시스템의 성능을 비교하였다. CCD의 신호응답특성은 입사선량에 비례하여 증가하였으며, CR과 FPD는 입사선량의 증가에 대수적 비례 관계를 보이면서 증가하였다. MTF는 CR과 FPD는 유사한 경향을 나타내었지만 CCD는 떨어지는 값을 나타내었다. WS는 FPD가 가장 낮았고, CR, CCD 순으로 증가하였다. DQE는 FPD, CR, CCD의 순으로 나타났다. DR 시스템은 영상수용체의 종류에 따라 서로 다른 영상 특성이 나타났다. 의료영상 획득 시 DR 시스템을 올바르게 사용하려면 영상의 물리적 특성을 정확히 알고 사용하는 것이 중요하다.

Keywords

References

  1. Schaetzing R., "Computed radiography technology", Proceeding of Radiological Society of North America, 10, 2003.
  2. KFDA, "A guide for general radiology of the patient dose recommend", 2012.
  3. Dobbins J. T., Ergun D.L., Rutz L., et al., "DQE (f) of four generations of computed radiography acquisition devices", Med. Phys., Vol. 22, No. 10, pp. 1581-1593, 1995. https://doi.org/10.1118/1.597627
  4. Jerrold T. B., Anthony S. J., Edwin M. L., et al., "The Essential Physics of Medical Imaging, 3nd ed.", Lippincott Williams & Wilkins, 2011.
  5. Antonuk L. E., Boudry J., and Huang W., "Demonstration of megavoltage and diagnostic X-ray imaging with hydrogenated amorphous silicon arrays", Med. Phys. Vol. 19, No. 6, pp. 1455-1466, 1992. https://doi.org/10.1118/1.596802
  6. Granfors P. R., and Aufrichtig R., "Performance of a $41{\times}41$-cm2 amorphous silicon flat panel X-ray detector for radiographic imaging applications", Med. Phys., Vol. 27, No. 6, pp. 1324-33, 2000. https://doi.org/10.1118/1.599010
  7. Finc C., Hallscheidt P. J., and Noeldge G., "Clinical comparative study with a large-area amorphous silicon flat-panel detector: image quality and visibility of anatomic structures on chest radiography", Am. J. Roentgenol, Vol. 178, No. 2, pp. 481-486, 2001.
  8. Bacher K., Smeets P., Bonnarens K., et al., "Dose reduction in patients undergoing chest imaging: digital amorphous silicon flat-panel detector radiography versus conventional filmscreen radiography and phosphor-based computed radiography", Am. J. Roentgenol, Vol. 181, No. 4, pp. 923-929, 2003. https://doi.org/10.2214/ajr.181.4.1810923
  9. ICRU (International Commission on Radiation Units and Measurements) Report No 41, "Modulation Transfer Function of Screen-Film Systems", Bethesda, 1986.
  10. IEC (International Electrotechnical Commission) 62220-1, "Medical electrical equipment Characteristics of digital X-ray imaging devices Part 1: determination of the detective quantum efficiency", Geneva, 2003.
  11. Fujita H., Tasai D. Y., and Itoh T., "A simple method for determining the modulation transfer function in digital radiography", IEEE Trans Med Imaging, Vol. 11, No. 1. pp. 34-39, 1992. https://doi.org/10.1109/42.126908
  12. Jung-Min Kim, "Edge Profile Correction for Modulation Transfer Function on Digital X-ray Imaging System", Journal of Radiological Science and Technology, Vol. 30, No. 3, pp. 251-257, 2007.
  13. Samei E., Flynn M. J., Reimann D. A., "A method for measuring the presampled MTF of digital radiographic systems using an edge test device. Med. Phys", Vol. 25, pp. 102-113, 1998. https://doi.org/10.1118/1.598165
  14. Kim J. M., Lee K. S. & Kim Y. H., "Correction Method of Wiener Spectrum (WS) on Digital Medical Imaging Systems", Journal of Radiological Science and Technology, Vol. 32, No. 1, pp. 17-24, 2009.
  15. Willis, C. E.,"Quality Improvement in Computed Radiography in Categorical Course in Physics: Technology Update and Quality Improvement of Diagnostic X-ray Imaging Equipment", Radiological Society of North America Publication (RSNA), pp. 153-160, 1996.
  16. Jeong H. W., Min J. W., Kim J. M., et al., "Performance Characteristic of a CsI(Tl) Flat Panel Detector Radiography System", Journal of Radiological Science and Technology, Vol. 35, No. 2, pp. 109-117, 2012.
  17. Kim, K. W., Jeong, H. W., Min, J. W., et al., "Measurement of Image Quality According to the Time of Computed Radiography System", Journal of Radiological Science and Technology, Vol. 38, No. 4, pp. 365-374, 2015. https://doi.org/10.17946/JRST.2015.38.4.05
  18. Kim, K. W., Jeong, H. W., Min, J. W., et al., "Evaluation of Image Quality for Various Electronic Portal Imaging Devices in Radiation Therapy", Journal of Radiological Science and Technology, Vol. 38, No. 4, pp. 451-461, 2015. https://doi.org/10.17946/JRST.2015.38.4.16
  19. Kim, K. W., Jeong, H. W., Min, J. W., et al., "Evaluation of the Modulation Transfer Function for Computed Tomography by Using American Association Physics Medicine Phantom", Journal of Radiological Science and Technology, Vol. 39, No. 2, pp. 193-198, 2016. https://doi.org/10.17946/JRST.2016.39.2.09
  20. Kim, K. W., Jeong, H. W., Min, J. W., et al., "Evaluation of the Performance Characteristic for Mammography by Using Edge device", Journal of Radiological Science and Technology, Vol. 39, No. 3, pp. 415-420, 2016. https://doi.org/10.17946/JRST.2016.39.3.16