NMR with excitation modulated by Frank sequences
NMR with excitation modulated by Frank sequences
复制标题
DOI：
10.1016/j.jmr.2009.03.009
复制
发表时间：
2009-07-01
影响因子：
2.2
通讯作者：
Greferath, Marcus
中科院分区：
文献类型：
--
作者：
Bluemich, Bernhard;Gong, Qingxia;Greferath, Marcus
小型化核磁共振在生物、化学和材料科学中越来越重要。除了磁铁，体积较大的部件是射频功率放大器和电源或电池组。结果表明，采用跟随特定类型的多相完美序列的恒定翻角调制激励，可以在较高响应峰值功率下获得较低的峰值激励功率。它在时间域和频率域都具有理想的功率分布。与传统的脉冲激励相比，峰值激励功率节省了六个数量级。其中，这种激发有望用于纽扣电池操作的微型核磁共振设备，以及在高场医学成像中遵守特定吸收率的规定。(C)2009 Elsevier Inc.保留所有权利。
Miniaturized NMR is of growing importance in bio-, chemical, and -material sciences. Other than the magnet, bulky components are the radio-frequency power amplifier and the power supply or battery pack. We show that constant flip-angle excitation with phase modulation following a particular type of polyphase perfect sequences results in low peak excitation power at high response peak power. It has ideal power distribution in both the time domain and the frequency domain. A savings in peak excitation power of six orders of magnitude has been realized compared to conventionally pulsed excitation. Among others, the excitation promises to be of use for button-cell operated miniature NMR devices as well as for complying with specific-absorption-rate regulations in high-field medical imaging. (C) 2009 Elsevier Inc. All rights reserved.