Time-resolved 3D quantitative flow MRI of the major intracranial vessels: Initial experience and comparative evaluation at 1.5T and 3.0T in combination with parallel imaging
Time-resolved 3D quantitative flow MRI of the major intracranial vessels: Initial experience and comparative evaluation at 1.5T and 3.0T in combination with parallel imaging
复制标题
DOI：
10.1002/mrm.21109
复制
发表时间：
2007-01-01
影响因子：
3.3
通讯作者：
Alley, Marcus T.
中科院分区：
文献类型：
--
作者：
Bammer, Roland;Hope, Thomas A.;Alley, Marcus T.
准确了解主要脑血管的血流特征对诊断脑血管异常具有重要意义。这涉及血流动力学关键区域的评估以及生物力学参数（如壁面剪切应力和压力梯度）的推导。采用并行成像的时间分辨3D相位对比（PC）MRI方法，在心动周期的多个实例中测量三维血流。从14名健康志愿者获得的4D速度数据被用来研究动态血流与使用多平面重组，3D流线，4D粒子追踪。此外，在1.5T和3T条件下，使用三种不同的并行成像缩减因子和三种不同的时间分辨率对14名受试者中的8名进行了比较评价，研究了磁场强度、并行成像和时间分辨率对数据的影响。由于并行成像性能更好，研究在3T下的执行速度始终快于1.5T。需要高时间分辨率（65 ms）来跟踪颅内血管中的动态过程。4D血流测量提供了高度的血管显著性。时间分辨流线分析提供了颅内血管系统先前未报告的特征。
Exact knowledge of blood flow characteristics in the major cerebral vessels is of great relevance for diagnosing cerebrovascular abnormalities. This involves the assessment of hemo-dynamically critical areas as well as the derivation of biome-chanical parameters such as wall shear stress and pressure gradients. A time-resolved, 3D phase-contrast (PC) MRI method using parallel imaging was implemented to measure blood flow in three dimensions at multiple instances over the cardiac cycle. The 4D velocity data obtained from 14 healthy volunteers were used to investigate dynamic blood flow with the use of multiplanar reformatting, 3D streamlines, and 4D particle tracing. In addition, the effects of magnetic field strength, parallel imaging, and temporal resolution on the data were investigated in a comparative evaluation at 1.5T and 3T using three different parallel imaging reduction factors and three different temporal resolutions in eight of the 14 subjects. Studies were consistently performed faster at 3T than at 1.5T because of better parallel imaging performance. A high temporal resolution (65 ms) was required to follow dynamic processes in the intracranial vessels. The 4D flow measurements provided a high degree of vascular conspicuity. Time-resolved streamline analysis provided features that have not been reported previously for the intracranial vasculature.