Spiral demystified
Spiral demystified
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DOI：
10.1016/j.mri.2010.03.036
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发表时间：
2010-07-01
影响因子：
2.5
通讯作者：
Hyacinthe, Jean-Noel
中科院分区：
文献类型：
--
作者：
Delattre, Benedicte M. A.;Heidemann, Robin M.;Hyacinthe, Jean-Noel
螺旋采集方案具有独特的优势，如流量补偿、有效的k空间采样和对运动的鲁棒性，使该方案成为其他非笛卡尔采样方案中的一个可行选择。因此，螺旋成像的主要应用在于动态磁共振成像，例如心脏成像和脑功能成像。然而，这些优点被实际困难所抵消，使得螺旋成像相当具有挑战性。首先，需要特别注意梯度波形及其硬件的设计。其次，这种数据的重建不再简单，因为k空间样本不再在笛卡尔网格上对齐。第三，为了利用并行成像技术，需要扩展常见的广义自动校准部分并行采集（GRAPPA）或灵敏度编码（SENSE）算法。最后，并且最值得注意的是，螺旋图像易于出现特定的伪影，例如由于梯度偏差和由B-0不均匀性和伴随的梯度场引起的非共振效应而导致的模糊。在这篇文章中，螺旋成像带来的各种困难，沿着，并提出了解决方案，在文献中，将详细审查。(C)2010年爱思唯尔公司All rights reserved.
Spiral acquisition schemes offer unique advantages such as flow compensation, efficient k-space sampling and robustness against motion that make this option a viable choice among other non-Cartesian sampling schemes. For this reason, the main applications of spiral imaging lie in dynamic magnetic resonance imaging such as cardiac imaging and functional brain imaging. However, these advantages are counterbalanced by practical difficulties that render spiral imaging quite challenging. Firstly, the design of gradient waveforms and its hardware requires specific attention. Secondly, the reconstruction of such data is no longer straightforward because k-space samples are no longer aligned on a Cartesian grid. Thirdly, to take advantage of parallel imaging techniques, the common generalized autocalibrating partially parallel acquisitions (GRAPPA) or sensitivity encoding (SENSE) algorithms need to be extended. Finally, and most notably, spiral images are prone to particular artifacts such as blurring due to gradient deviations and off-resonance effects caused by B-0 inhomogeneity and concomitant gradient fields. In this article, various difficulties that spiral imaging brings along, and the solutions, which have been developed and proposed in literature, will be reviewed in detail. (C) 2010 Elsevier Inc. All rights reserved.