Journal of radiological science and technology (대한방사선기술학회지:방사선기술과학)

Korean Society of Radiological Science (대한방사선과학회)
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Correlation Analysis of Control Factors in Automatic Exposure Control of Digital Radiography System Based on Fine Contrast Images

미세 대조도 영상을 기반한 디지털 방사선 영상 시스템의 자동노출제어 조절인자 간의 상관관계 분석

  • Lim, Se-Hun (Department of Radiology, ChungBuk National University Hospital) ;
  • Seoung, Youl-Hun (Department of Radiological Science, Graduate School of Health Sciences, Cheongju University)
  • 임세훈 (충북대학교병원 영상의학과) ;
  • 성열훈 (청주대학교 보건의료대학원 방사선학과)
  • Received : 2021.02.03
  • Accepted : 2021.02.21
  • Published : 2021.02.28
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Abstract

The purpose of this study was to analyze the effect of automatic exposure control (AEC) control factors in digital radiography systems based on the fine contrast images using coin phantoms. The AEC control factors were targeted at the range of dominent zone, sensitivity, and density. The dominent zone was divided into cases where a single coin was used to cover the field configuration, and cases where seven coins were used to cover the field configuration. The sensitivity was classified into three stages (200, 400, 800) and the density was classified into three stages (2.5, 0, 2.5). Image quality was evaluated by signal to noise ratio (SNR) and contrast to noise ratio (CNR). Then, the automatically exposed tube current was measured. As a result, the X-ray image of seven coins obtained a result value of about 1.2 times higher for SNR and 1.9 times higher for CNR than the X-ray image for one coin. The tube current was also about 1.6 times higher. In conclusion, In AEC, the higher the field configuration and dominent zone are matched and the higher the density, the lower the sensitivity, which increases the tube current and CNR, which increases the image quality. Therefore, it is judged that the appropriate setting of the range of dominent zone, sensitivity, and density of the control, which is the AEC control factor, could improve the fine contrast of images.

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