Radiological Physics and Technology

, Volume 11, Issue 4, pp 460–466 | Cite as

Improving image quality around subtle lung nodules by reducing artifacts in similar subtraction imaging

  • Hitomi NakamuraEmail author
  • Junji Morishita
  • Yoichiro Shimizu
  • Yongsu Yoon
  • Yusuke Matsunobu
  • Shigehiko Katsuragawa
  • Hidetake Yabuuchi


Similar subtraction imaging is useful for the detection of lung nodules; however, some artifacts on similar subtraction images reduce their utility. The authors attempted to improve the image quality of similar subtraction images by reducing artifacts caused by differences in image contrast and sharpness between two images used for similar subtraction imaging. Image contrast was adjusted using the histogram specification technique. The differences in image sharpness were compensated for using a pixel matching technique. The improvement in image quality was evaluated objectively based on the degree of artifacts and the contrast-to-noise ratio (CNR) of the lung nodules. The artifacts in similar subtraction images were reduced in 94% (17/18) of cases, and CNR was improved in 83% (15/18) of cases. The results indicate that the combination of histogram specification and pixel matching techniques is potentially useful in improving image quality in similar subtraction imaging.


Chest radiograph Computer-aided diagnosis Similar subtraction imaging 



The authors thank Keishin Kawamoto, M.Sc., R.T., Shun Tsubaki, M.Sc., R.T., Yusuke Kawazoe, B.Sc., R.T., and Yayoi Sakata, B.Sc, R.T. from the Morishita laboratory for their valuable contribution to discussion.

Compliance with ethical standards

Conflict of interest

All authors have no conflicts of interest to declare.

Ethics approval

All procedures in studies involving human participants were performed in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Informed consent

Requirements for informed consent were waived for all images used in this study by the Institutional Review Board.


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Copyright information

© Japanese Society of Radiological Technology and Japan Society of Medical Physics 2018

Authors and Affiliations

  • Hitomi Nakamura
    • 1
    Email author
  • Junji Morishita
    • 2
  • Yoichiro Shimizu
    • 1
  • Yongsu Yoon
    • 2
  • Yusuke Matsunobu
    • 1
  • Shigehiko Katsuragawa
    • 3
  • Hidetake Yabuuchi
    • 2
  1. 1.Department of Health Sciences, Graduate School of Medical SciencesKyushu UniversityFukuokaJapan
  2. 2.Department of Health Sciences, Faculty of Medical SciencesKyushu UniversityFukuokaJapan
  3. 3.Department of Radiological Technology, Faculty of Fukuoka Medical TechnologyTeikyo UniversityFukuokaJapan

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