Multiple Parallel Round Leg Design for Quadrature Birdcage Coil in Ultrahigh-Field MRI
Multiple Parallel Round Leg Design for Quadrature Birdcage Coil in Ultrahigh-Field MRI
复制标题
超高场MRI正交鸟笼线圈的多平行圆腿设计
DOI：
10.1007/s00723-017-0963-0
复制
发表时间：
2018-02
影响因子：
1
通讯作者：
Kai Zhong
中科院分区：
文献类型：
--
作者：
Yongfeng Xu;Qingqing Wen;Hongyi Yang;Kai Zhong
铜箔已广泛应用于磁共振成像 (MRI) 的传统射频 (RF) 鸟笼线圈。然而，对于超高场（UHF）MRI，由于邻近效应，铜箔上的电流密度分布集中在表面和边缘。这会增加有效电阻并扭曲鸟笼线圈上的圆周正弦电流分布，导致信噪比 (SNR) 较低且射频磁场 (B1) 场分布不均匀。在这种情况下，提出了多个平行圆线作为鸟笼线圈的腿，以优化电流密度分布并提高信噪比和 B1 场均匀性。该设计与用于 9.4 T (T) MRI 系统的三种具有不同宽度平条表面腿的传统鸟笼线圈进行了比较，例如窄腿鸟笼线圈 (NL)、中腿鸟笼线圈 (ML)、宽腿鸟笼线圈 (BL) 和多个平行圆线腿鸟笼线圈 (WL)。研究是在体外盐水模型以及体内小鼠大脑中进行的。与其他三种传统鸟笼式线圈相比，WL 表现出更高的线圈品质因数 Q 和更均匀的 B1 场分布。此外，与 NL、ML 和 BL 相比，WL 的 SNR 分别提高了 12%、10% 和 13%。有人提出，导体形状优化可能是提高 UHF MRI 射频线圈性能的有效方法。
Copper foil has been widely employed in conventional radio frequency (RF) birdcage coils for magnetic resonance imaging (MRI). However, for ultrahigh-field (UHF) MRI, current density distribution on the copper foil is concentrated on the surface and the edge due to proximity effect. This increases the effective resistance and distorts the circumferential sinusoidal current distribution on the birdcage coils, resulting in low signal-to-noise ratio (SNR) and inhomogeneous distribution of RF magnetic (B1) field. In this context, multiple parallel round wires were proposed as legs of a birdcage coil to optimize current density distribution and to improve the SNR and the B1field homogeneity. The design was compared with three conventional birdcage coils with different width flat strip surface legs for a 9.4 T (T) MRI system, e.g., narrow-leg birdcage coil (NL), medium-leg birdcage coil (ML), broad-leg birdcage coil (BL) and the multiple parallel round wire-leg birdcage coil (WL). Studies were carried out in in vitro saline phantom as well as in vivo mouse brain. WL showed higher coil quality factorQand more homogeneous B1field distribution compared to the other three conventional birdcage coils. Furthermore, WL showed 12, 10 and 13% SNR increase, respectively, compared to NL, ML and BL. It was proposed that conductor’s shape optimization could be an effective approach to improve RF coil performance for UHF MRI.
登录
查看更多内容
影响因子：
1
作者：
Yan X;Cao Z;Zhang X
通讯作者：
Zhang X
影响因子：
1
作者：
G. Giovannetti;G. Tiberi
通讯作者：
G. Giovannetti;G. Tiberi
DOI：
10.1002/cmr.b.20008
发表时间：
2004-04-01
影响因子：
0.9
作者：
Seeber, DA;Jevtic, I;Menon, A
通讯作者：
Menon, A
DOI：
10.1002/cmr.b.21271
发表时间：
2014-10
影响因子：
0.9
作者：
R. Stara;G. Tiberi;M. Gabrieli;G. Buonincontri;N. Fontana;A. Monorchio;M. Costagli;M. Symms;A. Retico;M. Tosetti
通讯作者：
R. Stara;G. Tiberi;M. Gabrieli;G. Buonincontri;N. Fontana;A. Monorchio;M. Costagli;M. Symms;A. Retico;M. Tosetti
影响因子：
3.3
作者：
Liu, WZ;Collins, CM;Smith, MB
通讯作者：
Smith, MB