Journal of the Korean Society of Radiology (한국방사선학회논문지)

The Korean Society of Radiology (한국방사선학회)
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The Dependence of CT Scanning Parameters on CT Number to Physical Density Conversion for CT Image Based Radiation Treatment Planning System

CT 영상기반 방사선치료계획시스템을 위한 CT수 대 물리적 밀도 변환에 관한 CT 스캐닝 매개변수의 의존성

  • Baek, Min Gyu (Department of Radiological Science, Kaya University) ;
  • Kim, Jong Eon (Department of Radiological Science, Kaya University)
  • 백민규 (가야대학교 방사선학과) ;
  • 김종언 (가야대학교 방사선학과)
  • Received : 2017.11.06
  • Accepted : 2017.11.30
  • Published : 2017.11.30
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Abstract

The dependence of CT scanning parameters on the CT number to physical density conversion from the CT image of CT and CBCT electron density phantom acquired by the CT scanner using in radiotherapy were analyzed by experiment. The CT numbers were independent of the tube current product exposure time, slice thickness, filter of image reconstruction, field of view and volume of phantom. But the CT numbers were dependent on the tube voltage and cross section of phantom. As a result, for physical density range above 0, the maximum CT number difference observed at the tube voltage between 90 and 120 kVp was 27%, and the maximum CT number difference observed between CT body and head electron density phantom was 15%.

방사선치료에 사용하는 CT 스캐너에 의해 획득된 CT 및 CBCT 전자밀도팬텀의 CT영상부터 CT수 대 물리적 밀도 변환에 관한 CT 스캐닝 매개변수의 의존성은 실험으로 분석하였다. CT수는 관전류량, 슬라이스 두께, 영상재구성 필터, 시야 그리고 팬텀 용적의 크기에 대해 의존하지 않았다. 그러나 CT수는 관전압과 팬텀 횡단면적 크기에 의존하였다. 결과로서, 물리적 밀도 1이상의 범위에 대하여, 90과 120 kVp 사이의 관전압에서 관측된 최대 CT수 차이는 27%이었고, 그리고 CT 몸통과 머리 전자밀도팬텀 사이에서 관측된 최대 CT수 차이는 15%이었다.

Keywords

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