Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
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A study on proper number of stimulations in functional MRI

뇌기능 활성화 검사 시 적정한 자극 횟수에 관한 연구

  • Son, Soon-Yong (Department of Health Science, Graduate School Hanyang University) ;
  • Kim, Yoon-Shin (Department of Health Science, Graduate School Hanyang University) ;
  • Choi, Kwan-Woo (Department of Radiology, Asan Medical Center) ;
  • Min, Jung-Whan (Department of Radiology, Shin-Gu University) ;
  • Lee, Jong-Seok (Department of Radiotechnology, Wonkwang Health Science University) ;
  • Yoo, Beong-Gyu (Department of Radiotechnology, Wonkwang Health Science University)
  • 손순룡 (한양대학교 대학원 보건학과) ;
  • 김윤신 (한양대학교 대학원 보건학과) ;
  • 최관우 (서울아산병원 영상의학과) ;
  • 민정환 (신구대학교 방사선과) ;
  • 이종석 (원광보건대학교 방사선과) ;
  • 유병규 (원광보건대학교 방사선과)
  • Received : 2012.08.27
  • Accepted : 2012.12.06
  • Published : 2012.12.31
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Abstract

BOLD technique in functional MRI has to apply multiple stimulations. However as the stimulation time increases failure rates rise. In this study we are proposing proper number of stimulations through our experiments. Ten normal people underwent functional MRI hand motor sanning and the paradigms were designed from first to seventh stimulation. Under Philips Intera Achieva 3.0T MR system and Invivo cop's Eloquence equipment, activation periods and rest periods were repeated ten times each, using BOLD EPI technique. Primary hand motor area stimulation and number of clusters, activation rates and number of activated clusters in and outside the region of interest were compared to each other. Number of clusters in region of interest was lower than others at second stimulation and became static from third stimulation. The stimulated ratios were elevated as the number of stimulations were increased but it was not proportional. Number of clusters outside the ROI became static from the third stimulation and started increasing from sixth stimulation. As results, given the activation ratios of ROI and out side the ROI, three times stimulation was the most appropriate because it does not affect accuracy, also decreasing the fatigue of patients by with the decreased scanning time.

BOLD기법은 자극 횟수가 늘어날수록 시간의 증가 및 검사 실패율이 높아지므로 본 연구를 통해 가장 적절한 자극 횟수를 도출하여 제시함을 목적으로 하였다. 연구대상은 정상인 10명을 대상으로 손 운동 기능검사의 paradigm을, 1회에서 7회까지 자극 횟수로 나누어 피검자에게 시행하였다. 실험장비는 Philips Intera Archieva 3.0T MRI System 및 Invivo사의 Eloquene를 사용하였으며, BOLD-EPI 기법을 이용하여 10번의 휴지기와 10번의 활성기의 block design을 이용하였다. 관심영역인 primary hand motor area의 활성화 여부와 활성화 cluster 수, 활성화도, 비관심영역의 활성화 cluster 수를 비교하였다. 관심영역의 활성화 cluster 수는 2회 자극이 가장 낮았고, 3회부터는 일정하였으며, 활성화도는 자극 횟수가 늘어날수록 증가하지만, 비례하지는 않았다. 비관심 영역의 활성화 cluster 수는 3회부터 일정하였고, 6회부터 다시 증가하였다. 결론적으로 관심영역과 비관심영역의 활성화를 감안하고, 시간 감소에 따른 환자의 피로를 감소시키면서 정확성에 영향을 주지 않는 자극 횟수로 3회가 적정하리라 사료된다.

Keywords

References

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