Journal of the Korean Society of Radiology (대한영상의학회지)

The Korean Society of Radiology (대한영상의학회)
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Radiation Doses of Dual-Energy CT for Abdominopelvic CT: Comparison with Single-Energy CT

복부-골반의 이중 에너지 CT에서의 방사선량: 단일 에너지 CT와의 비교

  • Cho, Young-Seo (Department of Radiology, Hanyang University Guri Hospital, Hanyang University College of Medicine) ;
  • Jeong, Woo-Kyoung (Department of Radiology, Hanyang University Guri Hospital, Hanyang University College of Medicine) ;
  • Kim, Yong-Soo (Department of Radiology, Hanyang University Guri Hospital, Hanyang University College of Medicine) ;
  • Heo, Jeong-Nam (Department of Radiology, Hanyang University Guri Hospital, Hanyang University College of Medicine)
  • 조영서 (한양대학교 의과대학 구리병원 영상의학과학교실) ;
  • 정우경 (한양대학교 의과대학 구리병원 영상의학과학교실) ;
  • 김용수 (한양대학교 의과대학 구리병원 영상의학과학교실) ;
  • 허정남 (한양대학교 의과대학 구리병원 영상의학과학교실)
  • Published : 2011.11.01
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Abstract

Purpose: To compare radiation doses of dual-energy CT (DECT) to single-energy CT (SECT) by a phantom experiment, with the application of mean tube currents for abdomino-pelvic CT. Materials and Methods: This study includes patients who were examined by contrast-enhanced CT for kidney evaluation. We divided the patients into six groups according to sex and body mass index. Each group consisted of five patients and a total of 30 patients were evaluated. We split the body parts (abdomen and pelvis), and calculated the mean tube current of each group as well as investigated the image noise. Applying the mean mAs from a CT scan, we measured the weighted CT dose index (CTDIw) of DECT and SECT. We compared the measured CTDIw to an estimated CTDI value displayed on the CT console. We also compared the radiation dose ratio of DECT to SECT (D/S ratio) for each subgroup. The radiation doses were compared by the student's t-test and analysis of variance. Results: The difference of image noise between DECT and SECT was not statistically significant. Radiation dose of DECT was higher than SECT by about 21.6% (10.69 mGy, 8.79 mGy; p < 0.0001), and the measured CTDI of the DECT was significantly higher than the estimated CTDI by about 6% (p < 0.001). The D/S ratio was not significant between the six groups. Conclusion: The measured CTDIw of abdominopelvic DECT studies were significantly higher than those of SECT.

목적: 성별과 체형에 따른 복부-골반 CT의 평균 관전류를 구한 후, 이를 적용한 팬텀 실험에서 단일 및 이중 에너지 CT의 가중 CT 선량지수를 비교하고자 하였다. 대상과 방법: 신장 검사를 위한 역동적 복부-골반 CT를 받은 환자 중 성별과 체질량 지수에 따라 5명씩 여섯 그룹 30명의 CT를 대상으로 하였다. 복부와 골반으로 나누어 평균 관전류의 그룹별 평균을 구하였고, 각각 CT 영상의 영상잡음을 구하였다. CT 선량지수 팬텀과 이온 챔버를 사용하여 각 평균 관전류를 적용한 단일, 이중 에너지 CT 스캔의 가중 CT 선량지수를 구한 후 비교하고, CT 스캐너 자체의 계산으로 얻어진 추정 CT 선량지수를 조사하여 각각 비교하였다. 또한 이중 에너지와 단일 에너지 CT의 방사선량의 비(D/S비)가 그룹 간 차이가 있는지 알아보았다. 통계적 방법으로 student t-test와 analysis of variance를 이용하였다. 결과: 이중 에너지와 단일 에너지 CT 간의 영상잡음은 유의한 차이를 보이지 않았다(p = 0.110). 이중 에너지 CT의 방사선 선량은 단일 에너지에 비해 약 21.6%가량 높았고(10.69 mGy, 8.79 mGy; p < 0.01), 이중 에너지 CT에서 측정된 CT 선량지수가 추정 CT 선량지수보다 약 6%가량 높았다(p < 0.01). 또한 D/S비는 성별, 체질량 지수, 신체 부분에 따라 뚜렷한 차이를 보이지 않았다. 결론: 복부-골반검사를 위한 이중 에너지 CT는 단일 에너지 CT에 비해 가중 CT 선량지수가 높다.

Keywords

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