Breath-hold water and fat imaging using a dual-echo two-point dixon technique with an efficient and robust phase-correction algorithm
Breath-hold water and fat imaging using a dual-echo two-point dixon technique with an efficient and robust phase-correction algorithm
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DOI：
10.1002/mrm.20146
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发表时间：
2004-08-01
影响因子：
3.3
通讯作者：
Ma, JF
中科院分区：
文献类型：
--
作者：
Ma, JF
提出了一种新的相位校正算法和双回波快速梯度回波脉冲序列的两点狄克逊技术。由于场的不均匀性，相位校正算法确定信号的方向分布而不是相位分布。具体地，区域生长方案使用信号相位的预先计算的空间梯度来指导生长序列，因此不需要手动选择种子或使用经验角度阈值。此外，给定像素的信号方向的确定是基于周围像素的幅度和相位两者的，其方向已经被确定。该算法的优点包括易于实现，计算效率高，并且在存在较大相位不确定性的像素时具有鲁棒性。该技术的可行性和实用性证明在体内与伪影的水和脂肪图像的整个腹部在一个单一的屏气。
A two-point Dixon technique using a novel phase-correction algorithm and commercially available dual-echo fast gradient-echo pulse sequence is presented. The phase-correction algorithm determines the directional rather than phase distribution of signals due to field inhomogeneities. Specifically, a region-growing scheme uses precalculated spatial gradients of the signal phase to guide the growth sequence, so there is no need to manually select the seeds or use an empirical angular threshold. Further, the determination of the signal direction of a given pixel is based on both the amplitude and phase of the surrounding pixels, the direction of which has already been determined. The advantages of this algorithm include its easy implementation, computational efficiency, and robustness in the presence of pixels with large phase uncertainty. The feasibility and usefulness of the technique are demonstrated in vivo with artifact-free water and fat images of an entire abdomen in a single breath-hold.