CARDIOVASCULAR FLOW DYNAMICS--IN VIVO STUDIES

该项目继续对心内血流动力学进行研究 彩色多普勒超声图像的数字化采集与分析 量化病理生理血流动力学异常的技术。 使用流体力学原理(喷流理论、动量连续性 保护、中心线加速、近端血流收敛和 湍流/粘性相互作用)，时间和空间量化 流量事件是可能的。 在临床处理瓣膜返流时，准确评估 反流的严重程度是非常重要的。多普勒波 超声心动图技术增强了非侵入性评估 瓣膜返流的症状。然而，到目前为止，还没有 与这些技术的临床适用性相关的研究使用 严格量化参比标准进行验证。海流 一年的努力延续了前几年在动物模型上的研究 慢性主动脉瓣反流：1)一种新的多普勒血流计算方法 它半自动地集成了数字空间和时间颜色 流速数据已被验证为返流物的定量 流。2)返流近端血流的三维重建 收敛记录了它的非对称半椭圆几何 允许计算最大回流流量。3)优秀的 在电磁导出的流速和 由流动的三维直接积分得到的结果 收敛弧长，以提供水流汇聚表面积。4) 允许进行左心室容积的三维重建 射血量、返流量和返流量的计算 分数。因此在体内得到验证的非侵入性多谱勒方法提供了 有关心脏瓣膜返流严重程度的可靠信息 帮助患者进行临床管理。

This project has continued studies of intracardiac flow dynamics with digital acquisition and analysis of color Doppler ultrasound imaging techniques for quantifying pathophysiologic hemodynamic abnormalities. Using hydrodynamic principles (jet flux theory, momentum continuity preservation, centerline acceleration, proximal flow convergence and turbulent/viscous interactions), temporal and spatial quantitation of flow events are possible. In the clinical management of valvular regurgitation, accurate evaluation of the severity of regurgitation is of major importance. Doppler echocardiographic techniques have enhanced the non invasive assessment of valvular regurgitation. However, there have been, heretofore, no studies related to the clinical applicability of these techniques using strictly quantified reference standards for validation. The current year's efforts have extended previous years' studies in an animal model of chronic aortic regurgitation: 1) A new Doppler flow calculation method which semiautomatically integrates digital spatial and temporal color flow velocity data has been validated for quantitation of regurgitant flow. 2) Three-dimensional reconstruction of regurgitant proximal flow convergence documented its asymmetric hemielliptical geometry which permitted calculation of peak regurgitant flow rates. 3) An excellent agreement was present between electromagnetically derived flow rates and those obtained from three-dimensional direct integration of flow convergence arc lengths to provide flow convergence surface area. 4) Three-dimensional reconstruction of left ventricular volumes permitted calculation of ejection volumes, regurgitant volumes and regurgitant fractions. Non invasive Dopler methods, thus validated in vivo, provide reliable information about the severity of cardiac valvular regurgitation to aid patient clinical management.