Hernando D, Haldar J P, Sutton B P, Ma J, Kellman P, Liang Z-P
Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
Magn Reson Med. 2008 Mar;59(3):571-80. doi: 10.1002/mrm.21522.
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 (LP). 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 LP 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.
在存在B₀场不均匀性的情况下进行水/脂肪分离是磁共振成像（MRI）中一个具有相当实际重要性的问题。本文描述了两种从狄克逊型采集数据估计水/脂肪图像和场不均匀性图的互补方法。一种基于可变投影（VARPRO），另一种基于线性预测（LP）。VARPRO方法非常稳健，由于其能够实现最大似然解，因此可用于低信噪比条件。LP方法在计算上更高效，并且在中等噪声和场不均匀性水平下表现良好。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，并纳入了几个实验的结果以展示它们的性能。
