한국의학물리학회지:의학물리 (Progress in Medical Physics)

  • 제21권3호
  • /
  • Pages.239-245
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  • 2010
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  • 2508-4445(pISSN)
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  • 2508-4453(eISSN)
한국의학물리학회 (Korean Society of Medical Physics)
권호 표지

직접 및 간접변환 방식의 디지털 유방 X선 촬영시스템의 영상화질 비교 연구

Comparison Study of Image Quality of Direct and Indirect Conversion Digital Mammography System

  • 박혜숙 (연세대학교 보건과학대학 방사선학과) ;
  • 오유나 (분당서울대학교병원 영상의학과) ;
  • 조희정 (분당서울대학교병원 영상의학과) ;
  • 김상태 (전북대학교 방사선과학기술학과) ;
  • 최유나 (연세대학교 보건과학대학 방사선학과) ;
  • 김희중 (연세대학교 보건과학대학 방사선학과)
  • Park, Hye-Suk (Department of Radiological Science, College of Health Science, Yonsei University) ;
  • Oh, Yu-Na (Department of Radiology, Seoul National University Bundang Hospital) ;
  • Jo, Hee-Jeong (Department of Radiology, Seoul National University Bundang Hospital) ;
  • Kim, Sang-Tae (Department of Radiation Science & Technology, Chonbuk National University) ;
  • Choi, Yu-Na (Department of Radiological Science, College of Health Science, Yonsei University) ;
  • Kim, Hee-Joung (Department of Radiological Science, College of Health Science, Yonsei University)
  • 투고 : 2010.05.24
  • 심사 : 2010.06.24
  • 발행 : 2010.09.30
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초록

본 연구의 목적은 직 간접 변환방식 검출기를 사용한 디지털 유방 X선 촬영시스템의 영상 화질을 비교하고 평가함에 있다. 영상의 정량적인 분해능을 나타내는 변조전달함수(MTF), 노이즈 특성을 나타내는 정규화된 잡음력 스펙트럼(NNPS), 그리고 신호 대 잡음비 성능을 나타내는 양자검출효율(DQE)인자를 이용하여 영상 화질평가를 하였다. DQE는 IEC 62220-1-2 규약에 따라 edge 팬텀을 사용한 MTF 도출을 이용하여 계산되었다. 대조도 대 노이즈비(CNR) 측정은 한국의료영상품질관리원에서 제시한 가이드라인에 따라 측정되었다. 직접 변환방식 검출기가 간접 변환방식 검출기에 비해 공간주파수별로 MTF와 DQE 값이 높은 것으로 측정되었다. 동일한 평균유선선량(AGD)일 때 직접 변환방식의 검출기는 더 높은 CNR값을 보였다. 공간주파수별로 높은 DQE 값을 갖는 직접 변환방식 검출기는 디지털 유방 X선 촬영시스템에 있어서 향상된 영상 화질과 적은 환자선량을 제공할 것이다.

The purpose of this study is to comprehensively compare and evaluate the characteristics of image quality for digital mammography systems which use a direct and indirect conversion detector. Three key metrics of image quality were evaluated for the direct and indirect conversion detector, the modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE), which describe the resolution, noise, and signal to noise performance, respectively. DQE was calculated by using a edge phantom for MTF determination according to IEC 62220-1-2 regulation. The contrast to noise ratio (CNR) was evaluated according to guidelines offered by the Korean Institute for Accreditation of Medical Image (KIAMI). As a result, the higher MTF and DQE was measured with direct conversion detector compared to indirect conversion detector all over spatial frequency. When the average glandular dose (AGD) was the same, direct conversion detector showed higher CNR value. The direct conversion detector which has higher DQE value all over spatial frequency would provide the potential benefits for both improved image quality and lower patient dose in digital mammography system.

키워드

참고문헌

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