Bunched Phase Encoding (BPE): A new fast data acquisition method in MRI
Bunched Phase Encoding (BPE): A new fast data acquisition method in MRI
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DOI：
10.1002/mrm.20819
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发表时间：
2006-03-01
影响因子：
3.3
通讯作者：
Duerk, JL
中科院分区：
文献类型：
--
作者：
Moriguchi, H;Duerk, JL
提出了一种新的快速数据采集方法--聚束相位编码法。在传统的直线数据采集中，当采集k空间数据时，仅应用读出梯度（并且没有相位编码梯度）。通过增加相位编码步长来减少相位编码线的数量通常会导致混叠伪影。Papoulis的广义采样理论断言，在某些情况下，即使在傅里叶域的某些区域违反了奈奎斯特准则，也可以重建混叠的无伪影信号。在这项研究中，Papoulis的理论结构被用来减少获得的相位编码线的数量。为了实现这一点，k空间数据在每次读出期间沿着“Z字形”轨迹进行采样;以高于正常直线采集的采样频率采集样本。TR周期的总数以及因此总扫描时间可以减少。当使用BIDE技术时，所得到的信噪比（SNR）通常在重建图像上变化，并且图像SNR取决于重建方法。这项工作可与基于梯度的并行成像版本相媲美。有证据表明，它可以作为MRI快速数据采集新机会的基础。Magn Reson Med 55：633-648，2006. (c)2006 Wiley-Liss，Inc.
A new fast data acquisition method, "Bunched Phase Encoding" (BPE), is presented. In conventional rectilinear data acquisition, only a readout gradient (and no phase encoding gradient) is applied when k-space data are acquired. Reduction of the number of phase encoding lines by increasing the phase encoding step size often leads to aliasing artifacts. Papoulis's generalized sampling theory asserts that in some cases aliasing artifact-free signals can be reconstructed even if the Nyquist criterion is violated in some regions of the Fourier domain. In this study, Papoulis's theoretical construct is exploited to reduce the number of acquired phase encoding lines. To achieve this, k-space data are sampled along a "zigzag" trajectory during each readout; samples are acquired at a sampling frequency higher than that of the normal rectilinear acquisition. The total number of TR cycles and, hence, the total scan time can be reduced. The resultant signal-to-noise ratio (SNR) often varies across the reconstructed image when using the BIDE technique, and the image SNR depends on the reconstruction method. This work is comparable to a gradient based version of parallel imaging. Evidence suggests it may serve as the basis for new opportunities for fast data acquisition in MRI. Magn Reson Med 55:633-648, 2006. (c) 2006 Wiley-Liss, Inc.