Multiresolution field map estimation using golden section search for water-fat separation
Multiresolution field map estimation using golden section search for water-fat separation
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DOI：
10.1002/mrm.21544
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发表时间：
2008-07-01
影响因子：
3.3
通讯作者：
Hargreaves, Brian A.
中科院分区：
文献类型：
--
作者：
Lu, Wenmiao;Hargreaves, Brian A.
许多诊断MRI序列需要可靠和均匀的脂肪抑制。基于化学位移引起的相位差的多点水脂分离方法在存在场不均匀性的情况下已经显示出巨大的成功。这项工作提出了一种计算效率高，鲁棒性强的场图估计方法。该方法首先将图像数据二次采样为多分辨率图像金字塔结构，然后利用黄金分割搜索直接在金字塔结构的粗级定位可能的场映射值。以有效的方式将场图估计细化并传播到越来越精细的分辨率，直到获得全分辨率场图以用于最终的水-脂肪分离。所提出的方法进行了验证与多回波序列，长回波间隔通常会带来很大的挑战，可靠的场图估计。
Many diagnostic MRI sequences demand reliable and uniform fat suppression. Multipoint water-fat separation methods, which are based on chemical-shift induced phase differences, have shown great success in the presence of field inhomogeneities. This work presents a computationally efficient and robust field map estimation method. The method begins with subsampling image data into a multiresolution image pyramidal structure, and then utilizes a golden section search to directly locate possible field map values at the coarsest level of the pyramidal structure. The field map estimate is refined and propagated to increasingly finer resolutions in an efficient manner until the full-resolution field map is obtained for final water-fat separation. The proposed method is validated with multiecho sequences where long echo-spacings normally impose great challenges on reliable field map estimation.