High-frequency Ultrasound Study Of The Effects Of Plaque Morphology On Hemodynamic Parameters

Cardiovascular disease (CVD) is the number one cause of death worldwide, as the number one killer, it also endangers the health of Chinese people. Atherosclerosis is the most common and most dangerous cardiovascular and cerebrovascular disease. Once a plaque ruptures, it will develop into thrombosis, which can completely block blood vessels, resulting in acute cardiovascular cerebrovascular events and even jeopardizing the lives of the human being. Therefore, it is very important to identify vulnerable plaques in patients in time and execute intervention treatment of cardiovascular and cerebrovascular diseases.Studies have shown that the development of atherosclerosis is closely related to the shear stress of vascular wall. So the study of plaque hemodynamic parameters is very significant in the prevention of plaque rupture. As for the impact of plaque morphology on hemodynamic parameters, there is just computer modeling to simulate plaques, but few researchers study this topic using vessel phantom or animal experiments.This paper adopts a two-dimensional flow field measurement and imaging technique, namely ultrasound particle image velocimetry (Echo Particle Image Velocimetry, Echo PIV), which is non-invasive and of high-resolution. This technique is used to study the effect of changes in plaque morphology on shear stress of arterial wall, which can provide a theoretical basis and guidance for early warning and clinical intervention of plaque rupture. This paper mainly does the following tasks:a. Design and produce molds for vascular phantoms. And according to freezing and thawing method, a series of vascular phantoms are made of PVA hydrogels. These phantoms have different plaque morphology with same hardness.b. Build a fluid circulation system which has the same period pulsation characteristics with human circulatory system. Pulsating flow generated by the pulsatile blood pump flows through liquid storage tank and transport pipeline and reaches to vessel phantom, which will produce a periodic contraction and relaxation. By controlling the frequency of pulsatile blood pump, stroke volume and systole/diastole ratio, the elastic vascular phantom can simulate human blood vessels and have the same motion features with human blood vessels'c. Do flow experiments in vitro, using particle image velocimetry. As a good tool, Echo PIV is used to process experimental data and get the distribution of blood flow velocity and shear stress. Using these distributions, this paper analyses the effects of plaque morphology on shear stress, and then deduce the impact of plaque morphology on plaque vulnerability.This paper mainly explores the relationship between plaque morphology and plaque vulnerability, this can help people to understand the development mechanism of cardiovascular and cerebrovascular and have important implications for therapeutic intervention.