Model for the correction of motion-induced phase errors in multishot diffusion-weighted-MRI of the head: Are cardiac-motion-induced phase errors reproducible from beat-to-beat?
Model for the correction of motion-induced phase errors in multishot diffusion-weighted-MRI of the head: Are cardiac-motion-induced phase errors reproducible from beat-to-beat?
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DOI：
10.1002/mrm.23245
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发表时间：
2012-08-01
影响因子：
3.3
通讯作者：
Bammer, R.
中科院分区：
文献类型：
--
作者：
O'Halloran, R. L.;Holdsworth, S.;Bammer, R.
在扩散加权成像中，由于扩散编码梯度期间运动引起的相位间的不一致，多次拍摄采集会出现问题。提出了大脑扩散加权 MRI 中运动引起的相位误差的模型，其中刚体运动和非刚体运动是分开的。在模型中，假设非刚体运动是由心脏搏动引起的，并且运动模式在每次心跳之间是可重复的。为了测试这一假设的有效性，在三名健康志愿者中量化了非刚体运动引起的相位误差的可重复性。发现非刚体运动引起的相位与脉搏血氧计波形显着相关（P < 0.05），类似于所有切片和受试者测试的 83% 的像素。 Magn Reson Med，2012。(C) 2011 Wiley periodicals, Inc.
In diffusion-weighted imaging, multishot acquisitions are problematic due to intershot inconsistencies of the phase caused by motion during the diffusion-encoding gradients. A model for the motion-induced phase errors in diffusion-weighted-MRI of the brain is presented, in which rigid-body and nonrigid-body motion are separated. In the model, it is assumed that nonrigid-body motion is due to cardiac pulsation, and that the motion patterns are repeatable from beat-to-beat. To test the validity of this assumption, the repeatability of nonrigid-body motion-induced phase errors is quantified in three healthy volunteers. Nonrigid-body motion-induced phase was found to significantly correlate (P < 0.05) with pulse-oximeter waveforms in similar to 83% of the pixels tested across all slices and subjects. Magn Reson Med, 2012. (C) 2011 Wiley Periodicals, Inc.