Fast and quiet MRI using a swept radiofrequency
Fast and quiet MRI using a swept radiofrequency
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DOI：
10.1016/j.jmr.2006.05.014
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发表时间：
2006-08-01
影响因子：
2.2
通讯作者：
Garwood, Michael
中科院分区：
文献类型：
--
作者：
Idiyatullin, Djaudat;Corum, Curt;Garwood, Michael
引入了一种新颖的快速而安静的磁共振成像方法（MRI），为医学和材料科学中的成像创造了新的机会。该方法称为Swift，具有傅立叶变换的扫描成像。在迅速的情况下，在核自旋的扫射射频激发时，以时间共享的方式获取时间域信号。在激发和信号采集之间可以忽略不计的时间，对于由具有非常快速的横向松弛速率的旋转组成的成像对象的新可能性，例如大分子，半固体和四极核。用于空间编码的现场梯度没有脉冲打开和关闭，而是以渐进的方式逐步逐步逐步逐步逐步逐步化，从而导致声噪声低。这种独特的采集方法有望对样品运动相对不敏感，这对于成像活物体很重要。此外，与常规MRI相比，频率扫描激发在时间上分布了信号能量，因此，适当信号数字化的动态范围要求减少。为了进行演示，显示了塑料对象和皮质骨的图像。 （c）2006 Elsevier Inc.保留所有权利。
A novel fast and quiet method of magnetic resonance imaging (MRI) is introduced which creates new opportunities for imaging in medicine and materials science. The method is called SWIFT, sweep imaging with Fourier transformation. In SWIFT, time-domain signals are acquired in a time-shared manner during a swept radiofrequency excitation of the nuclear spins. With negligible time between excitation and signal acquisition, new possibilities exist for imaging objects consisting of spins with extremely fast transverse relaxation rates, such as macromolecules, semi-solids, and quadrupolar nuclei. The field gradient used for spatial-encoding is not pulsed on and off, but rather is stepped in orientation in an incremental manner, which results in low acoustic noise. This unique acquisition method is expected to be relatively insensitive to sample motion, which is important for imaging live objects. Additionally, the frequency-swept excitation distributes the signal energy in time and thus dynamic range requirements for proper signal digitization are reduced compared with conventional MRI. For demonstration, images of a plastic object and cortical bone are shown. (c) 2006 Elsevier Inc. All rights reserved.