지원사업
학술연구/단체지원/교육 등 연구자 활동을 지속하도록 DBpia가 지원하고 있어요.
커뮤니티
연구자들이 자신의 연구와 전문성을 널리 알리고, 새로운 협력의 기회를 만들 수 있는 네트워킹 공간이에요.
논문 기본 정보
- 자료유형
- 학술대회자료
- 저자정보
- 발행연도
- 2014.10
- 수록면
- 413 - 416 (4page)
이용수
초록· 키워드
오류제보하기
Despite the effect of radio frequency (RF) shield on the birdcage coil leading to degradation of RF signal sensitivity in the imaging region, RF shield has to be considered for preventing the electro-magnetic field interaction between RF coil and MR scanner. Although the RF shield decreases overall transverse magnetic field (B₁) and RF transmit (B₁+) sensitivity compared to un-shielded volume coil, optimal RF shield configuration and positioning are critical issues in small-animal MR scanner.
In this study, we demonstrated that improper positioning of un-shield RF birdcage (BC) coil leads to inhomogeneous B₁ + distribution at 7 Tesla. The flip angle (FA) map and the S-parameter measurement of custom-built 8-leg BC coil were performed when rotating its coil by 5° in the azimuthally angle. The results clearly show that an inhomogeneous FA map was measured in all cases due to the coil-subject interaction and improper positioning of BC coil. The mean valuesfor reference angles at 55°, +100° and + 220° of BC coil were 56.9, 54.5 and 58.3, respectively. Standard deviation (SD) value of for reference angles at 55°, +100° and + 220° of BC coil were measured to be 2.5, 2.7 and 2.3. The differentiation of mean and SD value of rotating angles indicate inhomogeneity and their sensitivity of B₁+ field. The proper positioning of BC coil in the MR scanner is crucial in shielding RF in the small-animal MR scanner.
In this study, we demonstrated that improper positioning of un-shield RF birdcage (BC) coil leads to inhomogeneous B₁ + distribution at 7 Tesla. The flip angle (FA) map and the S-parameter measurement of custom-built 8-leg BC coil were performed when rotating its coil by 5° in the azimuthally angle. The results clearly show that an inhomogeneous FA map was measured in all cases due to the coil-subject interaction and improper positioning of BC coil. The mean valuesfor reference angles at 55°, +100° and + 220° of BC coil were 56.9, 54.5 and 58.3, respectively. Standard deviation (SD) value of for reference angles at 55°, +100° and + 220° of BC coil were measured to be 2.5, 2.7 and 2.3. The differentiation of mean and SD value of rotating angles indicate inhomogeneity and their sensitivity of B₁+ field. The proper positioning of BC coil in the MR scanner is crucial in shielding RF in the small-animal MR scanner.
목차
Abstract
1. Introduction
2. Material and Methods
3. Results
4. Conclusion and Discussions
References
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UCI(KEPA) : I410-ECN-0101-2016-560-000990167