7T vs. 4T: RF power, homogeneity, and signal-to-noise comparison in head images
7T vs. 4T: RF power, homogeneity, and signal-to-noise comparison in head images
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DOI：
10.1002/mrm.1156
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发表时间：
2001-07-01
影响因子：
3.3
通讯作者：
Ugurbil, K
中科院分区：
文献类型：
--
作者：
Vaughan, JT;Garwood, M;Ugurbil, K
在7 T和4 T磁场强度下检查了信噪比（SNR）、射频场（B）和人体头部成像的射频功率要求。7 T时B的变化幅度几乎是4 T时的两倍（相似度为42%与相似度为23%）。在7 T下头部中心的90度脉冲所需的功率大约是4 T下的两倍。与4 T相比，在7 T下大脑上平均的SNR至少高1.6倍。这些实验结果与使用人类头部模型和麦克斯韦方程进行的计算一致，（C）2001 Wiley-Liss，Inc.
Signal-to-noise ratio (SNR), RF field (B,), and RF power requirement for human head imaging were examined at 7T and 4T magnetic field strengths. The variation in B, magnitude was nearly twofold higher at 7T than at 4T (similar to 42% compared to similar to 23%). The power required for a 90 degrees pulse in the center of the head at 7T was approximately twice that at 4T, The SNR averaged over the brain was at least 1.6 times higher at 7T compared to 4T, These experimental results were consistent with calculations performed using a human head model and Maxwell's equations, (C) 2001 Wiley-Liss, Inc.