Simulated phase evolution rewinding (SPHERE): A technique for reducing B-0 inhomogeneity effects in MR images
Simulated phase evolution rewinding (SPHERE): A technique for reducing B-0 inhomogeneity effects in MR images
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DOI：
10.1002/mrm.1910380416
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发表时间：
1997-10-01
影响因子：
3.3
通讯作者：
Hu, XP
中科院分区：
文献类型：
--
作者：
Kadah, YM;Hu, XP
本文提出了一种降低磁共振图像场非均匀性效应的新方法。观察到图像退化是由数据采集过程中B-o非均匀性引起的相位累积引起的，本方法基于图像的初始估计和相应的场图，在k空间数据中对累积的相位进行数值倒卷。倒带过程生成一个校正的k空间数据集，该数据集随后进行傅里叶变换以产生最终图像。本文对该方法进行了理论分析，并对该技术在磁共振成像数据中的应用进行了理论分析，结果表明该方法是一种适用于各种序列的通用方法。将该方法应用于单次回波平面成像、中心重排序的分段回波平面成像和螺旋序列的实验数据，结果表明，该方法对降低B-o不均匀性引起的图像退化具有鲁棒性。
A novel method for reducing field inhomogeneity effects in magnetic resonance images is described in this paper. Observing that image degradation arises from B-o inhomogeneity-induced phase accrual during data acquisition, the present method numerically rewinds the accumulated phase in the k-space data based on an initial estimate of the image and a corresponding field map. The rewinding process generates a corrected k-space data set that is subsequently Fourier transformed to produce the final image. In this paper, a theoretical analysis of the method and applications of the technique to magnetic resonance imaging data are presented, The theoretical analysis of the method indicates that it is a general approach applicable to a variety of sequences. Results obtained by applying the method to experimental data acquired with single-shot echo-planar imaging, segmented echo-planar imaging with centric reordering, and spiral sequences demonstrate that it is robust in reducing image degradation induced by B-o inhomogeneity.