Gennisson Jean-Luc, Lerouge Sophie, Cloutier Guy
Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center, Montreal, Quebec, Canada.
Ultrasound Med Biol. 2006 Oct;32(10):1529-37. doi: 10.1016/j.ultrasmedbio.2006.06.008.
Blood clotting is a natural process that can be both beneficial and life-threatening for the human body. It allows the maintenance of hemostasis after vascular injury, but it can also cause deep vein thrombosis and heart stroke. This study aimed better to understand the clotting process from a biomechanical point of view by using an acoustic method. The long-term objective is the staging of the age of clots in deep veins for therapy planning. The transient elastography method using a shear elasticity probe served to evaluate the shear wave velocity (V(S)) and shear wave attenuation (alpha(S)) of porcine whole blood during in vitro clot formation. By solving an inverse problem, it was then possible to provide images of the elasticity (mu(B)) and of the viscosity (eta(B)) from clotting blood. The time-varying elasticity and viscosity were very similar to what has been observed for the sol-gel transition of polymers. The mechanical properties of blood clot, which were modified by varying the hematocrit and by adding heparin or fibrinogen, were clearly assessed by the transient elastography technique. It is concluded that the shear elasticity probe is an appropriate tool to quantify and follow the sol-gel transition of blood during clotting.
血液凝固是一个对人体既有益又可能危及生命的自然过程。它能在血管损伤后维持止血，但也可能导致深静脉血栓形成和中风。本研究旨在通过声学方法从生物力学角度更好地理解凝血过程。长期目标是对深静脉中血栓的形成时间进行分期，以用于治疗规划。使用剪切弹性探头的瞬态弹性成像方法用于评估猪全血在体外凝血过程中的剪切波速度（V(S)）和剪切波衰减（alpha(S)）。通过解决一个反问题，进而有可能提供凝血过程中血液弹性（mu(B)）和粘度（eta(B)）的图像。随时间变化的弹性和粘度与聚合物的溶胶-凝胶转变过程中所观察到的非常相似。通过改变血细胞比容以及添加肝素或纤维蛋白原对血凝块力学性能进行的改变，可通过瞬态弹性成像技术清晰地评估。结论是，剪切弹性探头是定量和跟踪血液在凝血过程中溶胶-凝胶转变的合适工具。
