Radiological Physics and Technology

, Volume 9, Issue 1, pp 109–115 | Cite as

Effect of X-ray beam quality on determination of exposure index

  • Shogo YasumatsuEmail author
  • Nobukazu Tanaka
  • Kensuke Iwase
  • Yoichiro Shimizu
  • Junji Morishita


We investigated the effect of X-ray beam qualities RQA3, 5, 7, and 9 on the exposure index (EI) as defined by International Electrotechnical Commission guideline 62494-1. Half-value layers (HVLs) of RQA5 X-rays passing through anti-scatter grids (grid ratios 6:1, 8:1, 10:1, and 12:1) were also evaluated because grids are frequently used in clinical situations. The maximum percent differences in the EIs for RQA3, 7, and 9 with respect to RQA5 were 35.0, 11.6, and 38.7 %, respectively. The range of HVLs for RQA5–7 beams was 7.10–9.10 mm of aluminum (mm Al). This was wider than the range of HVLs when grids were used (6.94–7.29 mm Al). The effect of variations in X-ray beam qualities in the RQA series on the EI was significantly greater than the effect of grids. This study indicated that, in clinical settings, the EI should be used carefully in X-ray examinations with different X-ray beam qualities.


Exposure index X-ray beam quality Digital radiography Computed radiography Anti-scatter grid 



The authors are grateful to the editor in chief of this journal, Kunio Doi, Ph.D., The University of Chicago. We also thank the editors and the editorial assistant of this journal, Mrs. Elisabeth Lanzl, for providing initial and final polishing of the submitted manuscript in improving the readability and English expressions, and the reviewers for giving us useful comments and suggestions for improving our manuscript.

Compliance with ethical standards

Conflict of interest

We have nothing to declare for this study.


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Copyright information

© Japanese Society of Radiological Technology and Japan Society of Medical Physics 2015

Authors and Affiliations

  • Shogo Yasumatsu
    • 1
    Email author
  • Nobukazu Tanaka
    • 2
  • Kensuke Iwase
    • 1
  • Yoichiro Shimizu
    • 1
  • Junji Morishita
    • 3
  1. 1.Department of Health Sciences, Graduate School of Medical SciencesKyushu UniversityFukuokaJapan
  2. 2.Department of Radiological Science, Faculty of Health SciencesJunshin Gakuen UniversityFukuokaJapan
  3. 3.Department of Health Sciences, Faculty of Medical SciencesKyushu UniversityFukuokaJapan

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