Motion Artifact Correction in Free-Breathing Abdominal MRI Using Overlapping Partial Samples to Recover Image Deformations
Motion Artifact Correction in Free-Breathing Abdominal MRI Using Overlapping Partial Samples to Recover Image Deformations
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DOI：
10.1002/mrm.22017
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发表时间：
2009-08-01
影响因子：
3.3
通讯作者：
Atkinson, D.
中科院分区：
文献类型：
--
作者：
White, M. J.;Hawkes, D. J.;Atkinson, D.
本文提出了一种在没有任何外部传感器或导航仪测量的情况下，在自由呼吸过程中连续采集肝脏MRI数据的方法。当与k空间数据相关的变形已知时，广义矩阵求逆重建已被证明在减少运动的重影和模糊伪影方面是有效的。本文描述了一种获得这些非刚性变形的新方法。呼吸模型是由快速动态序列建立的：配准低空间分辨率的图像，并通过整体上下位移来参数化它们的变形。然后，通过将k空间的几行与来自变形的参考图像的等效线进行比较，同时在模型参数上改变变形，来找到后续成像数据的每个子集的正确变形。此过程称为使用重叠部分样本的图像变形恢复(IDROPS)。使用10项来自志愿者的快速动态研究进行的模拟显示，iDROPS导致的肝脏内畸形的平均误差为1.43毫米。另外四名志愿者接受了更高空间分辨率的成像。使用来自几个呼吸周期的数据的完整重建过程被证明减少了肝脏的模糊和重影。使用iDROPS参数还显示了回溯性呼吸门控。《医学评论》62：440-449,2009。(C)2009年Wiley-Liss，Inc.
This article presents a method to reconstruct liver MRI data acquired continuously during free breathing, without any external sensor or navigator measurements. When the deformations associated with k-space data are known, generalized matrix inversion reconstruction has been shown to be effective in reducing the ghosting and blurring artifacts of motion. This article describes a novel method to obtain these nonrigid deformations. A breathing model is built from a fast dynamic series: low spatial resolution images are registered and their deformations parameterized by overall superior-inferior displacement. The correct deformation for each subset of the subsequent imaging data is then found by comparing a few lines of k-space with the equivalent lines from a deformed reference image while varying the deformation over the model parameter. This procedure is known as image deformation recovery using overlapping partial samples (iDROPS). Simulations using 10 rapid dynamic studies from volunteers showed the average error in iDROPS-derived deformations within the liver to be 1.43 mm. A further four volunteers were imaged at higher spatial resolution. The complete reconstruction process using data from throughout several breathing cycles was shown to reduce blurring and ghosting in the liver. Retrospective respiratory gating was also demonstrated using the iDROPS parameterization. Magn Reson Med 62:440-449, 2009. (C) 2009 Wiley-Liss, Inc.