Dynamics of respiratory and cardiac CSF motion revealed with real-time simultaneous multi-slice EPI velocity phase contrast imaging
Dynamics of respiratory and cardiac CSF motion revealed with real-time simultaneous multi-slice EPI velocity phase contrast imaging
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DOI：
10.1016/j.neuroimage.2015.07.073
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发表时间：
2015-11-15
期刊：
影响因子：
5.7
通讯作者：
Feinberg, David A.
中科院分区：
文献类型：
--
作者：
Chen, Liyong;Beckett, Alexander;Feinberg, David A.
脑脊液 (CSF) 动力学主要通过心门控相位对比 MRI 进行研究，结合来自多个心动周期的信号来创建一个时间平均心动周期的电影相位采样。心脏和呼吸变化对脑脊液运动的相对影响尚不清楚。脑室、脑池和蛛网膜下腔中的脑脊液可能存在呼吸驱动的运动，但尚未通过速度测量来表征。迄今为止，常用的速度成像电影相位对比技术本质上无法检测呼吸速度变化，因为几分钟内获取的心脏门控数据使呼吸相位贡献随机化。我们开发了一种极快、实时、定量的 MRI 技术，可在 30 秒内同时进行 3 或 6 个切片级别的同步多切片 (SMS) 回波平面成像 (EPI) 采集，对 CSF 速度进行成像，并观察 CSF 速度的 3D 空间分布。对 10 名受试者进行了测量，利用呼吸带记录呼吸阶段和视觉提示来指导受试者呼吸频率。协议能够在 4 分钟内测量覆盖有 24 个轴向切片的大脑和基底池区域内的速度，并在 3 个速度方向上重复。这些测量是在整个大脑中进行的，而不是在选定的线区域中进行，以便可以可视化脑脊液动态的全局视图。对心脏和呼吸驱动的脑脊液动力学的观察表明，双向呼吸运动主要沿着中轴发生，穿过基底池和心室内通道，并在较小程度上发生在周围侧裂中，而蛛网膜下腔中存在很少的脑脊液运动。在吸气阶段，脑脊液向上（从下到上）运动进入颅腔和侧脑室，而在呼气阶段则方向相反。 (C) 2015 Elsevier Inc. 保留所有权利。
Cerebrospinal fluid (CSF) dynamics have been mostly studied with cardiac-gated phase contrast MRI combining signal from many cardiac cycles to create cine-phase sampling of one time-averaged cardiac cycle. The relative effects of cardiac and respiratory changes on CSF movement are not well understood. There is possible respiration-driven movement of CSF in ventricles, cisterns, and subarachnoid spaces which has not been characterized with velocity measurements. To date, commonly used cine-phase contrast techniques of velocity imaging inherently cannot detect respiratory velocity changes since cardiac-gated data acquired over several minutes randomizes respiratory phase contributions. We have developed an extremely fast, real-time, and quantitative MRI technique to image CSF velocity in simultaneous multi-slice (SMS) echo planar imaging (EPI) acquisitions of 3 or 6 slice levels simultaneously over 30 s and observe 3D spatial distributions of CSF velocity. Measurements were made in 10 subjects utilizing a respiratory belt to record respiratory phases and visual cues to instruct subjects on breathing rates. A protocol is able to measure velocity within regions of brain and basal cisterns covered with 24 axial slices in 4 minutes, repeated for 3 velocity directions. These measurements were performed throughout the whole brain, rather than in selected line regions so that a global view of CSF dynamics could be visualized. Observations of cardiac and breathing-driven CSF dynamics show bidirectional respiratory motion occurs primarily along the central axis through the basal cisterns and intraventricular passageways and to a lesser extent in the peripheral Sylvian fissure with little CSF motion present in subarachnoid spaces. During inspiration phase, there is upward (inferior to superior) CSF movement into the cranial cavity and lateral ventricles and a reversal of direction in expiration phase. (C) 2015 Elsevier Inc. All rights reserved.