超声向量血流图对人体左心室涡流的初步探讨

Evaluation of vortex of left ventricular by noninvasive vector flow mapping with Doppler echocardiography

目的应用向量血流图（vector flow mapping，VFM）初步研究人体左心室内流场结构，寻求人体左心室内漩涡形成规律及漩涡描述参数。方法选取60名健康志愿者为观察对象，应用VFM技术得到心腔内血流速度向量和流线图，采用DSA—RS1软件测量漩涡直径、漩涡位置、漩涡最大向量速度及漩涡圈数。结果应用VFM技术可清晰显示心腔内血流速度的矢量图，观察结果显示舒张早期和晚期通过二尖瓣V1的血流在左室内形成两个相对靠近二尖瓣环的小漩涡，且前者比后者的漩涡向量速度高，漩涡圈数多（P〈0．05）；而舒张中期和等容收缩期左室内的回旋血流形成一个较大的涡环，且前者比后者的漩涡向量速度高，漩涡圈数多（P〈0．05）。结论VFM图像能显示心室内血液流场的变化，研究得出的涡描述参数能够反映这一变化，并能初步定量研究心腔内复杂流场结构。

Objective To evaluate the human left ventricular flow field structure by vector flow mapping （VFM） ,and to seek the formation rules and description parameters of swirl vortex in the human left ventricular. Methods Sixty heathy adults were involved. The velocity distribution images on the section plane of the flow in the left ventricular were obtained by VFM, and series parameters of vortex including vortex diameter（transverse and vertical diameter）, vortex position （transverse and longitudinal position）, vortex maximum flow velocity （Vmax） and density number of vortex ring（N） were measured with the software named DSA RS1. Results A pair of similar vortex showed by VFM in the left ventricle of the heart during the early and late diastole period which were formed by a strong jet flow through the mitral valve were small vortex,and Vmax and N in former were bigger than that in latter（ P ~11. 05 ） , while a bigger vortex ring continued during the middle diastolic and isovolumic contraction period with a trailing jet in the left ventricle were large whirlpool, and Vmax and N in former were bigger than that in latter（ P 〈0. 05）. Conclusions Changes of the intraventricular blood flow field structure can be showed by VFM, and description parameters of vortex concluded from the study can reflect the changes,which can be used as a preliminary quantitative study of the complex flow field structure in heart chamber.