Joint estimation of water/fat images and field inhomogeneity map
Joint estimation of water/fat images and field inhomogeneity map
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DOI：
10.1002/mrm.21522
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发表时间：
2008-03-01
影响因子：
3.3
通讯作者：
Liang, Z. -P.
中科院分区：
文献类型：
--
作者：
Hernando, D.;Haldar, J. P.;Liang, Z. -P.
在B - 0场不均匀的情况下进行水/脂肪分离在磁共振成像（MRI）中是一个具有相当重要实际意义的问题。本文介绍了两种从迪克森（Dixon）类型采集中估计水/脂肪图像和场不均匀性图的互补方法。一种基于变量投影（VARPRO），另一种基于线性预测（LIP）。VARPRO方法非常稳健，由于其能够实现最大似然解，所以可在低信噪比条件下使用。LIP方法计算效率更高，并且在中等噪声水平和场不均匀性条件下表现良好。这些方法已扩展到通过联合求解所有线圈的估计问题来处理多线圈采集。对这两种方法进行了分析和比较，并包含了几个实验的结果以展示它们的性能。
Water/fat separation in the presence of B-0 field inhomogeneity is a problem of considerable practical importance in MRI. This article describes two complementary methods for estimating the water/fat images and the field inhomogeneity map from Dixon-type acquisitions. One is based on variable projection (VARPRO) and the other on linear prediction (LIP). The VARPRO method is very robust and can be used in low signal-to-noise ratio conditions because of its ability to achieve the maximum-likelihood solution. The LIP method is computationally more efficient, and is shown to perform well under moderate levels of noise and field inhomogeneity. These methods have been extended to handle multicoil acquisitions by jointly solving the estimation problem for all the coils. Both methods are analyzed and compared and results from several experiments are included to demonstrate their performance.