Accuracy and limitations of vector flow mapping: left ventricular phantom validation using stereo particle image velocimetory.
Accuracy and limitations of vector flow mapping: left ventricular phantom validation using stereo particle image velocimetory.
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DOI：
10.1007/s12574-016-0321-5
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发表时间：
2017-06
影响因子：
1.6
通讯作者：
Nishiyama T
中科院分区：
文献类型：
--
作者：
Asami R;Tanaka T;Kawabata KI;Hashiba K;Okada T;Nishiyama T
采用左心室体模对矢量流标测（VFM）的准确性与立体粒子图像测速（stereo-PIV）测量结果进行了对比研究。VFM是一种超声心动图方法，通过从质量守恒方程估计血流的方位角分量来可视化二维血流动力学。VFM提供了可视化心脏血流的方法，但还没有一项研究将VFM估计的血流与其他方法获得的血流数据进行比较。在光学和声学透明的左心室体模中创建了可再现的三维心脏血流，该体模允许在同一平面上同时采集彩色血流图（CFM）数据和立体PIV。将VFM算法应用于CFM数据，并将得到的VFM估计和立体PIV数据进行比较，以评估VFM的精度。通过VFM和立体PIV获得的速度场在主要流动特征和主要涡流特征的时间过程转变方面非常一致，即，VFM和PIV矢量的总体相关性为R = 0.87（p < 0.0001）。该算法的精度受CFM信号分辨率和三维流动的共同影响，违背了算法的平面流动假设。向量的统计分析显示，在一个心动周期的CFM速度范围内，差异的标准差平均为4.5%，并且该值根据心动周期的相位波动高达10%。VFM提供了相当准确的二维血流信息的心脏血流动力学。这些关于VFM准确性的发现为基于VFM的诊断提供了基础。
The accuracy of vector flow mapping (VFM) was investigated in comparison to stereo particle image velocimetry (stereo-PIV) measurements using a left ventricular phantom. VFM is an echocardiographic approach to visualizing two-dimensional flow dynamics by estimating the azimuthal component of flow from the mass-conservation equation. VFM provides means of visualizing cardiac flow, but there has not been a study that compared the flow estimated by VFM to the flow data acquired by other methods. A reproducible three-dimensional cardiac blood flow was created in an optically and acoustically transparent left-ventricle phantom, that allowed color-flow mapping (CFM) data and stereo-PIV to be simultaneously acquired on the same plane. A VFM algorithm was applied to the CFM data, and the resulting VFM estimation and stereo-PIV data were compared to evaluate the accuracy of VFM. The velocity fields acquired by VFM and stereo-PIV were in excellent agreement in terms of the principle flow features and time-course transitions of the main vortex characteristics, i.e., the overall correlation of VFM and PIV vectors was R = 0.87 (p < 0.0001). The accuracy of VFM was suggested to be influenced by both CFM signal resolution and the three-dimensional flow, which violated the algorithm’s assumption of planar flow. Statistical analysis of the vectors revealed a standard deviation of discrepancy averaging at 4.5% over the CFM velocity range for one cardiac cycle, and that value fluctuated up to 10% depending on the phase of the cardiac cycle. VFM provided fairly accurate two-dimensional-flow information on cardio-hemodynamics. These findings on VFM accuracy provide the basis for VFM-based diagnosis.