Journal of radiological science and technology (대한방사선기술학회지:방사선기술과학)

Korean Society of Radiological Science (대한방사선과학회)
권호 표지
DOI QR코드

DOI QR Code

A Case Study of Application of Exposure Index in Computed Radiography by Using Human Chest Phantom

인체 흉부 모형 팬텀을 이용한 컴퓨터방사선영상에서 노출지수의 적용 사례 연구

  • Jeong, Hoi-Woun (Department of Radiological Science, Baekseok Culture University) ;
  • Min, Jung-Whan (Department of Radiological Technology, Shingu College)
  • Received : 2018.08.06
  • Accepted : 2018.12.17
  • Published : 2018.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

As the use of digital radiographic system has been expanded, there are some concerns an increase about in patient of radiation dose. Therefore, International Electro-technical Commission (IEC) has been proposed a standard foe exposure index (EI). In this study, the EI was measured on human chest model using computed radiography (CR). Radiation quality used RQA5 of IEC62494-1. After acquiring the chest anterior posterior image (Chest AP) by using the phantom, the EI was obtained by applying the system response. In this study, we have analyzed the images with the detector size (Full filed ROI) and the optimized image (Fit filed ROI). The EI increased proportionally with radiation dose increase. Due to the discrete increase in pixel value, the EI showed an exponential increase. The discrete increase in noise equivalent quanta (NEQ) resulted in a discrete increase in the EI. The EI of the two images used in this study increased with increasing NEQ but showed different increments. For the measurement of the EI, IEC standards must be followed. The EI should be used as an index to evaluate the image quality for quality control of X-ray image rather than as an indicator of exposure dose. When calculating the EI, the system response should be applied depending on whether or not the grid is used. The size of the field should be obtained by including only the necessary parts.

Keywords

References

  1. Kim JS, Kim JM, Lee YH, Seo DN, Choi IS, Nam SR, et al. National Data Analysis of General Radiography Projection Method in Medical Imaging. Journal of Radiological Science and Technology. 2014;37(3):169-75.
  2. ICRP Publication 93. Managing patient dose in digital radiology. 2003.
  3. International Electrotechnical Commission(IEC), IEC 62494-1. Medical electrical equipment-Exposure index of digital X-ray imaging systems. Part 1: Definition and requirements for general radiography. Ed. 1. 2008.
  4. Kishimoto K, Ariga E, Ishigaki R, Imai M, Kawamoto K, Kobayashi K, et al. Study of Appropriate Dosing in Consideration of Image Quality and Patient Dose on the Digital Radiography. Japanese Journal of Radiological Technology. 2011;67(11):1381-97. https://doi.org/10.6009/jjrt.67.1381
  5. Kim KW, Jeong HW, Min JW, et al. Measurement of Image Quality According to the Time of Computed Radiography System. Journal of Radiological Science and Technology. 2015;38(4):365-74. https://doi.org/10.17946/JRST.2015.38.4.05
  6. Kim KW, Jeong HW, Min JW, et al. Evaluation of the Modulation Transfer Function for Computed Tomography by Using American Association Physics Medicine Phantom. Journal of Radiological Science and Technology. 2016;39(2):193-8. https://doi.org/10.17946/JRST.2016.39.2.09
  7. Kim KW, Jeong HW, Min JW, et al. Evaluation of the Performance Characteristic for Mammography by Using Edge device. Journal of Radiological Science and Technology. 2016;39(3):415-20. https://doi.org/10.17946/JRST.2016.39.3.16
  8. Schaetzing R. Computed radiography technology. Proceeding of Radiological Society of North America. 2003;10
  9. Dobbins JT, Ergun DL, Rutz L, et al. DQE (f) of four generations of computed radiography acquisition devices. Med. Phys. 1995;22(10):1581-93. https://doi.org/10.1118/1.597627
  10. Antonuk LE, Boudry J, Huang W. Demonstration of megavoltage and diagnostic X-ray imaging with hydrogenated amorphous silicon arrays. Med. Phys. 1992;19(6):1455-66. https://doi.org/10.1118/1.596802
  11. International Electrotechnical Commission(IEC), IEC 62220-1. Medical electrical equipment Characteristics of digital X-ray imaging devices Part 1: determination of the detective quantum efficiency. Geneva. 2003.
  12. Jeong HW, Min JW, Kim JM, et al. Performance Characteristic of a CsI(Tl) Flat Panel Detector Radiography System. Journal of Radiological Science and Technology. 2012;35(2):109-17.
  13. Jeong HW, Min JW, Kim JM, et al. Investigation of Physical Imaging Properties in Various Digital Radiography System. Journal of Radiological Science and Technology. 2017;40(3):363-70. https://doi.org/10.17946/JRST.2017.40.3.02
  14. Ariga E. Evaluation of Calibration Error for Applying Exposure Index. Japanese Journal of Radiological Technology. 2011;67(11):1433-7. https://doi.org/10.6009/jjrt.67.1433
  15. Nakamae M, Miyajima Y, Nakano T, Kitanaka Y, Okura Y. Influence of Interest Region and Interest Value Settings on Exposure Index Analysis Using Chest Clinical Images. Japanese Journal of Radiological Technology. 2014;70(11):1250-7. https://doi.org/10.6009/jjrt.2014_JSRT_70.11.1250
  16. Willis CE. "Quality Improvement in Computed Radiography" in Categorical Course in Physics: Technology Update and Quality Improvement of Diagnostic X-ray Imaging Equipment, R. G. Gould and J. M. Boone (eds.). Oak Brook, IL: Radiological Society of North America Publication (RSNA). 1996:153-60.