Automatic correction of in-plane bulk motion artifacts in self-navigated radial MRI
Automatic correction of in-plane bulk motion artifacts in self-navigated radial MRI
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DOI：
10.1016/j.mri.2007.08.001
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发表时间：
2008-04-01
影响因子：
2.5
通讯作者：
Poptani, Harish
中科院分区：
文献类型：
--
作者：
Kim, Sungheon;Dougherty, Lawrence;Poptani, Harish
放射状核磁共振通常用于对不可避免的运动敏感的扫描。虽然通过相位校正可以很容易地从径向轨迹数据中去除平移运动伪影，但旋转运动的校正仍然是放射状磁共振成像中的一个挑战。我们提出了一种新的方法来重新聚焦在视点交错的放射状MRI数据中被视点到视点运动所污染的图像。该方法将旋转视角误差建模为视角阶数的多项式函数，通过最小化自导航图像的图像熵、梯度熵、归一化梯度平方和均方差来估计模型参数。平移运动矫正是通过对齐投影轮廓进行的。为了验证平移和旋转运动校正方法在不同噪声水平下的稳健性，进行了仿真研究。该方法已成功应用于健康受试者的运动矫正。采用一阶或二阶模型对图像进行运动校正，其相对误差均小于5%。这项研究展示了该方法在运动敏感应用中的潜力。(C)2008年，爱思唯尔公司出版。
Radial MRI is typically used for scans that are sensitive to unavoidable motion. While the translational motion artifact can be easily removed from the radial trajectory data by phase correction, correction of rotational motion still remains a challenge in radial MRI. We present a novel method to refocus the image corrupted by view-to-view motion in the view-interleaved radial MRI data. In this method, the error in rotational view angles was modeled as a polynomial function of the view order and the model parameters were estimated by minimizing the self-navigator image metrics such as image entropy, gradient entropy, normalized gradient squared and mean square difference. Translational motion correction was conducted by aligning the projection profiles. Simulation studies were conducted to demonstrate the robustness of both translational and rotational motion correction methods in different noise levels. The proposed method was successfully applied to correct for motion of healthy subjects. Substantial motion correction with relative error of less than 5% was achieved by using either first- or second-order model with the image metrics. This study demonstrates the potential of the method for motion-sensitive applications. (c) 2008 Published by Elsevier Inc.