Advertisement

The Standardized Exposure Indicator

  • Euclid Seeram
Chapter

Abstract

This chapter addressed essential features of the international standardized EI for DR imaging systems. First, two “old” propriety scales for the EI, the inverse scale and the proportional scale, were reviewed briefly followed by an outline of a generalized method for determining the EI. The next topic described are three conditions for the IEC standardized EI that must be met: (a) the standardized EI is related to the detector exposure and the standardized EI is obtained from the pixel values in the region of interest, (b) the standardized EI uses a linear proportional scale related to the detector exposure/signal (i.e., doubling the detector dose doubles the standardized EI value), and (c) consideration of the radiation beam quality (kVp, half-value layer, and added filtration) used for the calibration of the EI and the precision of the scale. Additionally, selected terminology of the IEC standardized EI are defined and include the exposure index (EI), the target EI (EIT), deviation index (DI), and the value of interest (VOI).

The IEC standardized EI is now proportional to the detector exposure and requires the user to establish EIT values for all examinations in order to ensure optimization of the dose to the patient without compromising the image quality. These values (EI and EIT) can now be used to calculate the DI. The DI provides immediate feedback to the technologist as to whether the correct exposure was used for the examination. The chapter concludes with an example of a dose-image quality optimization study for the purpose of providing insights as to how a department may go about establishing EIT values objectively.

It is important to note that sections of this chapter have been previously published in Journal of Medical Imaging and Radiation Sciences 45 (2014) 144–158, entitled The New Exposure Indicator for Digital Radiography,” and some of the content has been taken from my PhD thesis, entitled Optimization of the Exposure Indicator as a Dose Management Strategy in Computed Radiography. PhD Dissertation (Charles Sturt University, New South Wales, Australia, 2014).

References

  1. 1.
    Seibert JA, Morin RL. The standardized exposure index for digital radiography: an opportunity for optimization of radiation dose to the pediatric population. Pediatr Radiol. 2011;41:573–81.CrossRefGoogle Scholar
  2. 2.
    Gibson DJ, Davidson R. Exposure creep in CR: a longitudinal study. Acad Radiol. 2012;19:458–62.CrossRefGoogle Scholar
  3. 3.
    Neitzel U. Ending a state of confusion: NACP optimization course. Hamberg: Philips healthcare, diagnostic X-ray; 2013.Google Scholar
  4. 4.
    Brake DA. A standardized exposure index for digital radiography. Radiol Technol. 2016;87(5):581–5.PubMedGoogle Scholar
  5. 5.
    International Electrotechnical Commission. IEC 62494-1 ed. 1 Medical electrical equipment exposure index of digital X-ray imaging systems, part 1: definitions and requirements for general radiography, Geneva: IEC; 2008. p. 2008.Google Scholar
  6. 6.
    American Association of Physicists in Medicine (AAPM) Report No 116. An exposure indicator for digital radiography. College Park, MD: American Association of Physicists in Medicine; 2009.Google Scholar
  7. 7.
    Bushberg J, Seibert AJ, Leidholdt M, Boone JM. The essential physics of medical imaging. 3rd ed. Philadelphia: Lippincott Williams & Wilkins; 2012.Google Scholar
  8. 8.
    Willis CE, Slovis TL. Conference on the ALARA (as low as reasonably achievable) concept in pediatric CR intelligent dose reduction. Pediatr Radiol. 2004;34(Suppl. 3):S159–247.Google Scholar
  9. 9.
    Van Metter R, Yorkston J. Toward a universal definition of speed for digitally acquired projection images. In: Flynn MJ, Hsieh J, editors. Medical imaging 2006: physics of medical imaging. San Diego, CA: Society of Photo-optical Instrumentation Engineers; 2006. p. 442–25.Google Scholar
  10. 10.
    Shepard JS, Wang J, Flynn M. An exposure indicator for digital radiography: AAPM task group 116 (executive summary). Med Phys. 2009;36(7):2898–914.CrossRefGoogle Scholar
  11. 11.
    Don S, MacDougall R, Strauss K, et al. Image gently back to basics initiative: ten steps to help manage radiation dose in pediatric digital radiography. Am. J Roentgenology. 2013;200(5):W431–6.CrossRefGoogle Scholar
  12. 12.
    Seeram E, Davidson R, Bushong S, Swan H. Optimizing the exposure indicator as a dose management strategy in computed radiography. Radiol Technol. 2016;87(4):380–91.PubMedGoogle Scholar
  13. 13.
    Moore Q, Don S, Goske M. Image gently: using exposure indicators to improve pediatric digital radiography. Radiol Technol. 2012;84(1):93–9.PubMedGoogle Scholar
  14. 14.
    Seeram E. The new exposure indicator for digital radiography. J Med Imaging Radiat Sci. 2014;45:144–15.CrossRefGoogle Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  • Euclid Seeram
    • 1
    • 2
    • 3
    • 4
    • 5
  1. 1.Medical Radiation Sciences University of SydneySydneyAustralia
  2. 2.Medical Radiation Sciences, Faculty of Health SciencesUniversity of SydneySydneyAustralia
  3. 3.Adjunct Associate Professor, Medical Imaging and Radiation SciencesMonash UniversityClaytonAustralia
  4. 4.Adjunct Professor, Faculty of ScienceCharles Sturt UniversityWagga WaggaAustralia
  5. 5.Adjunct Associate Professor, Medical Radiation Sciences, Faculty of HealthUniversity of CanberraBruceAustralia

Personalised recommendations