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A research on improving signal to noise ratio for magnetic resonance imaging through increasing filling factor inside surface coil

자기공명 검사시 코일 내 filling factor 증가를 통한 신호대 잡음비의 향상에 관한 연구

  • 최관우 (서울아산병원 영상의학과) ;
  • 손순룡 (서울아산병원 영상의학과)
  • Received : 2012.08.16
  • Accepted : 2012.11.08
  • Published : 2012.11.30

Abstract

MRI signals are significantly reduced by the magnetic field inhomogenity result from human body itself being consisted of various materials like air, fat, muscle, bone and blood vessels. In this study we used silicon which is tissue equivalent to compensate wound body shapes. Objects were eight adults who do not have any special symptoms. Feet were scanned because of their complicated structures and consequently signal reduction occurs a lot. Thirty images were acquired from the middle of arcus pedis longitudinalis including five distal phalanges parallel to the line connecting metatarsal bone and phalanges. SNR data from bones and soft tissues were compared before and after sticking silion between toes and paired t test was performed. It was came out that SNR data from bone and soft tissue were both significantly higher after applying silicon on both T1 and T2 weighted images and it was statistically meaningful having positive corelation. As a result, this study dramatically increases SNR without affecting object by increasing the object volume inside the surface coil.

인체는 공기, 지방, 근육, 뼈, 혈관과 같이 서로 다른 조직으로 구성되어 있어 각 조직간 자화율 차이로 인해 자장의 불균일이 항상 발생하여 신호가 감소한다. 이에 본 연구에서는 서로 다른 조직으로 구성된 인체의 신호감소를 해결하기 위하여 인체의 조직밀도와 유사한 실리콘을 이용하여 공기와 맞닿은 굴곡진 부분에 보상함으로써 자기공명영상의 신호를 높이고자 하였다. 특별한 증상이 없는 성인 8명으로 대상으로 하였으며, 인체 중 굴곡이 많고 구조가 복잡해 신호감소가 많이 발생하는 발을 설정하였다. 영상은 종족궁의 가운데부터 5개의 말절골을 포함하여 얻었으며, 중족골 및 족지골을 연장한 선에 평행하게 30절편을 얻었다. 측정은 실리콘의 적용 전 후 뼈와 연부조직의 SNR을 비교하였으며, 대응표본 T검정을 이용하여 통계분석 하였다. 연구결과 뼈와 연부조직의 T1, T2 강조영상 모두 실리콘 적용 후가 적용 전에 비해 SNR이 월등히 높게 나왔으며 유의한 양의 상관관계로 증가하였다. 결론적으로 본 연구는 체적소에 영향을 주지 않으면서 코일내 인체의 부피를 늘린 획기적인 개선 방법으로, 본질적 문제인 체적소의 부피나 균일성 저하를 해결하여 SNR을 높일 수 있었다.

Keywords

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