CARDIOVASCULAR APPLICATIONS OF VECTOR FLOW IMAGING

利用连续波进行血流定量和定性分析 多普勒、脉冲多普勒和多普勒彩色血流成像技术， 成为广泛临床应用中不可或缺的诊断工具 应用. 然而，从这些信息中获得的信息质量 技术受到两个基本限制的严重影响： 仅定义三维血液的一个投影的能力 速度矢量，以及对于后两种技术，混叠。 我们的团队开创了技术和仪器， 这些限制显著地扩展了流数据的质量。 初始 结果表明，二维矢量流（VF）技术， 能够精确地量化速度， 沿着成像平面内的所有方向沿着限制， 多普勒角度估计 此外，最初的体外研究 显示出准确量化速度剖面和体积的能力， 层流容器和射流中的流速，流动角度为90度， 多普勒仪器故障。 我们建议进行模拟、体外和临床研究， 研究基于并行接收的新型矢量流技术 加工，提供精确的，角度独立的测量高 在临床上具有挑战性的应用中的血流速度。 具体地说， 我们将这项研究的重点放在量化的射流，其中， 高速度和大流动梯度占优势。 性能 VF和多普勒方法定量体外射流将是 使用校准的计算机控制的体模进行比较。 这些研究 将包括临床相关的动量和近端流量分析 速度、噪音水平和湍流。 此外，试点临床 研究提出了调查性能的VF方法， 定量二尖瓣和主动脉瓣反流束中的高速流动， 与连续波多普勒相比， 对于这样的测量。 假设VF成像将增加 临床测量的准确性和容易性在这样的要求 应用程序，并将提供一致的测量，无论 使用的声学窗口。

Quantitative and qualitative analyses of blood flow using continuous wave Doppler, pulsed Doppler, and Doppler color flow imaging techniques have become indispensable diagnostic tools in a wide range of clinical applications. However, the quality of information obtained from these techniques is severely compromised by two fundamental limitations: the ability to define only one projection of the three-dimensional blood velocity vector and, for the latter two techniques, aliasing. Our group has pioneered techniques and instrumentation that overcome these limitations and markedly extend the quality of flow data. Initial results indicate that two-dimensional vector flow (VF) techniques are capable of accurately quantifying velocities well beyond Doppler aliasing limits, along all directions within the imaging plane, without requiring Doppler angle estimation. In addition, initial in vitro studies have shown the ability to accurately quantify velocity profiles and volumetric flow rates in laminar vessels and jets, at flow angles of 90degrees where Doppler instruments fail. We propose to undertake simulation, in vitro, and clinical studies to examine novel vector flow techniques, based on parallel receive processing, that provide accurate, angle independent measurement of high blood velocities in clinically challenging applications. Specifically, we focus this research on quantification of regurgitant jets, in which high velocities and large flow gradients predominate. The performance of VF and Doppler methods of quantifying in vitro jet flow will be compared using a calibrated, computer-controlled phantom. These studies will include momentum and proximal flow analyses at clinically relevant velocities, noise levels, and turbulence. In addition, pilot clinical studies are proposed to investigate the performance of the VF methods in quantifying high velocity flow in mitral and aortic regurgitant jets, with comparison to continuous wave Doppler, the clinical gold standard for such measurements. It is hypothesized that VF imaging will increase the accuracy and ease of clinical measurements in such demanding applications and will provide consistent measurements regardless of the acoustic window utilized.