Lipid suppression for brain MRI and MRSI by means of a dedicated crusher coil
Lipid suppression for brain MRI and MRSI by means of a dedicated crusher coil
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DOI：
10.1002/mrm.25331
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发表时间：
2015-06-01
影响因子：
3.3
通讯作者：
Klomp, Dennis W. J.
中科院分区：
文献类型：
--
作者：
Boer, Vincent O.;van de Lindt, Tessa;Klomp, Dennis W. J.
目的MR脑成像和光谱学中的脂质抑制一直是一个长期存在的问题，为此开发了各种技术。大多数方法是基于反转恢复或空间或光谱选择性激发的脂质信号，然后由移相。所有技术都需要额外的RF脉冲、梯度破碎器和延迟，这增加了序列的持续时间和复杂性。此外，脂质信号是差shimmed，是由不同的共振频率，具有不同的松弛properties.MethodsIn这项工作中，提出了一种新的方法，用于抑制颅外脂质，通过一个外部体积的破碎机线圈。它是基于表面破坏梯度的原则，产生一个非常本地和不均匀的磁场在外层的头部，从而破坏了相位相干的颅外signals.ResultsDephasing的信号可以被纳入几乎任何序列，因为它只需要一个短脉冲的线圈，并不需要额外的RF脉冲或延迟。脂质抑制的例子都显示在梯度回波成像和光谱imaging.ConclusionOuter体积压碎允许简单的脂肪抑制和提高扫描效率，这是特别有益的超高场强。Magn Reson Med 73：2062-2068，2015年。(c)2014 Wiley Periodicals，Inc.
PurposeLipid suppression in MR brain imaging and spectroscopy has been a long-standing problem for which various techniques have been developed. Most methods are based on inversion recovery or spatially or spectrally selective excitation of the lipid signal followed by dephasing. All techniques require additional RF pulses, gradient crushers and delays, which increase the duration and complexity of sequences. In addition, the lipid signal is poorly shimmed, and is composed of different resonance frequencies that have different relaxation properties.MethodsIn this work, a novel approach for suppression of extra cranial lipids is presented, by means of an outer volume crusher coil. It is based on the principle of surface spoiling gradients, which generate a very local and inhomogeneous magnetic field in the outer layer of the head, and thereby destroys the phase coherence of the extra cranial signals.ResultsDephasing of the signal can be incorporated in almost any sequence because it requires only a short pulse of the coil, and does not require additional RF pulses or delays. Examples of lipid suppression are shown in both gradient echo imaging and spectroscopic imaging.ConclusionOuter volume crushing allows for simple fat suppression and boosts scanning efficiency, which is particularly beneficial at ultra-high field strengths. Magn Reson Med 73:2062-2068, 2015. (c) 2014 Wiley Periodicals, Inc.