Investigations on the efficiency of cardiac-gated methods for the acquisition of diffusion-weighted images
Investigations on the efficiency of cardiac-gated methods for the acquisition of diffusion-weighted images
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DOI：
10.1016/j.jmr.2005.07.005
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发表时间：
2005-11-01
影响因子：
2.2
通讯作者：
Clare, S
中科院分区：
文献类型：
--
作者：
Nunes, RG;Jezzard, P;Clare, S
扩散加权图像本质上对运动非常敏感。脑的脉动运动可引起伪信号衰减，导致表观扩散系数的高估，即使使用快照回波平面成像。这种错误的计算会导致对主要扩散方向的错误估计。可以执行心脏门控，以将采集限制在周期的安静部分。虽然有效，但这种方法导致明显更长的采集时间。另一方面，已经证明，在胼胝体上方的区域中脉动运动不显著。为了减少采集时间并提高全脑心脏门控采集的效率，可以在心脏收缩期间对大脑的上部切片进行成像，从而为受脉动运动影响最大的那些切片保留最大的空间。这种优化方法的优点和缺点进行了研究，在这里，比较一个更标准的门控方法和非门控方法。(c)2005年爱思唯尔公司All rights reserved.
Diffusion-weighted images are inherently very sensitive to motion. Pulsatile motion of the brain can give rise to artifactual signal attenuation leading to over-estimation of the apparent diffusion coefficients, even with snapshot echo planar imaging. Such miscalculations can result in erroneous estimates of the principal diffusion directions. Cardiac gating can be performed to confine acquisition to the quiet portion of the cycle. Although effective, this approach leads to significantly longer acquisition times. On the other hand, it has been demonstrated that pulsatile motion is not significant in regions above the corpus callosum. To reduce acquisition times and improve the efficiency of whole brain cardiac-gated acquisitions, the upper slices of the brain can be imaged during systole, reserving diastole for those slices most affected by pulsatile motion. The merits and disadvantages of this optimized approach are investigated here, in comparison to a more standard gating method and to the non-gated approach. (c) 2005 Elsevier Inc. All rights reserved.