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Evaluation of overexposure risk when there is a space between the subject and the couch in computed tomography: a phantom study

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Abstract

The purpose of this study was to investigate the risk of overexposure associated with automatic tube current modulation (ATCM) and automatic couch height positioning compensation mechanism (AHC) in computed tomography (CT) systems, particularly in scenarios involving a gap between the subject and the couch. Results revealed that when AHC was enabled, CT dose index volume (CTDIvol) increased by approximately 10% at 2.5 cm, 20% at 5.0 cm, and 40% at 10.0 cm gaps compared to close contact conditions. While the AHC function ensures consistent exposure doses and image quality regardless of subject positioning relative to the CT gantry isocenter, the study highlights a potential risk of overexposure when a gap exists between the subject and the couch. These findings offer valuable insights for optimizing CT imaging protocols and underscore the importance of carefully considering subject positioning in clinical practice.

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Acknowledgements

I extend my sincere gratitude to all my senior colleagues at the hospital whose invaluable guidance and support significantly contributed to this paper. Their wealth of clinical experience and insightful advice greatly influenced my research direction. I am truly thankful for their patient mentorship, thoughtful discussions, and responsiveness to my inquiries, all of which enhanced the depth of this work.

Funding

The authors did not receive support from any organization for the submitted work.

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Authors and Affiliations

  1. Division of Clinical Radiology Service, Okayama Central Hospital, 6-3, Ishimakitamachi, Kitaku, Okayama, 700-0017, Japan

    Yuta Fujiwara, Yoshiki Kamihoriuchi, Fumie Higuchi, Shinichi Nakayama, Yutako Ohyama, Tomoko Sasaki & Shinsaku Watanabe

  2. Department of Radiological Technology, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, Matsushima, Kurashiki, Okayama, 288701-0193, Japan

    Takanori Masuda

Authors
  1. Yuta Fujiwara
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  2. Yoshiki Kamihoriuchi
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  3. Fumie Higuchi
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  4. Shinichi Nakayama
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  5. Yutako Ohyama
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  6. Tomoko Sasaki
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  7. Shinsaku Watanabe
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  8. Takanori Masuda
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Contributions

Conceptualization: Yuta Fujiwara. Methodology: Yuta Fujiwara, Yoshiki Kamihoriuchi, Fumie Higuchi, and Takanori Masuda. Formal analysis and investigation: Yutako Ohyama, Tomoko Sasaki, and Yuta Fujiwara. Writing—original draft preparation: Yuta Fujiwara. Writing—review and editing: Shinichi Nakayama and Takanori Masuda. Project administration: Shinsaku Watanabe. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Yuta Fujiwara.

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Conflict of interest

All the authors declare that they have no conflict of interest.

Ethical statement

This article did not contain any studies involving human participants.

Consent to participate

Informed consent was obtained from all individual participants included in the study.

Data availability Statement

Raw data were generated at Okayama Central Hospital. Derived data supporting the findings of this study are available from the corresponding author Y.Fujiwara on request.

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Fujiwara, Y., Kamihoriuchi, Y., Higuchi, F. et al. Evaluation of overexposure risk when there is a space between the subject and the couch in computed tomography: a phantom study. Radiol Phys Technol 17, 561–568 (2024). https://doi.org/10.1007/s12194-024-00804-y

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  • DOI: https://doi.org/10.1007/s12194-024-00804-y

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