CARDIOVASCULAR FLOW DYNAMICS--IN VIVO STUDIES

该项目继续研究心内血流动力学， 彩色多普勒超声图像的数字化采集与分析 用于量化病理生理血流动力学异常的技术。 利用流体动力学原理（射流通量理论，动量连续性 保留、中心线加速、近端血流会聚和 湍流/粘性相互作用），时间和空间定量 流事件是可能的。 在瓣膜返流的临床治疗中， 反流的严重程度非常重要。 多普勒 超声心动图技术增强了非侵入性评估 瓣膜返流然而，迄今为止，没有 与这些技术的临床适用性相关的研究， 用于验证的严格量化的参考标准。 当前 今年的努力扩展了前几年在动物模型中的研究 慢性主动脉瓣返流的多普勒血流计算方法 它半自动地将数字空间和时间色彩 已验证流速数据可用于定量分析 流 2)近端血流的三维重建 收敛证明了它的不对称半椭圆几何， 允许计算峰值流速。 3)一个优秀 电磁导出的流速与 从三维流动直接积分得到的那些 会聚弧长以提供流动会聚表面积。四、 允许左心室容积的三维重建 计算射血容量、回血容量和回血容量 分数。 因此，在体内验证的非侵入性Dopler方法提供了 关于心脏瓣膜返流严重程度的可靠信息 以帮助患者临床管理。

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.