心血管疾病是最常見的非傳染性疾病，每年約帶走1780萬的生命。其中，心血管疾病最常見的病因是因為動脈粥樣硬化，而壁剪切應力是造成動脈粥樣硬化的原因之一。壁面剪切應力被認為是血流動力學的一個重要參數，並影響著血管內皮細胞的生長。內皮細胞功能障礙會導致動脈粥樣硬化中的血管平衡損失，從而導致心脈衝波傳播的速度異常。動脈粥樣硬化病變發展機制的相互作用複雜，在動物研究中測量壁面切應力和脈搏波速度也仍然存在許多問題。因此，在動物研究中，用來同時量測壁剪切應力和心脈衝波傳播速度作為研究工具為未來了解疾病發展機制是必要的。
本研究提出了基於40 MHz高頻超音向量都卜勒測量小鼠的頸動脈壁剪切應力成像和心脈衝波速度成像，並應用時間標記技術來解決混疊發生。在仿體實驗中，我們設計了穩定流實驗和脈動流實驗，以驗證在模擬小鼠頸動脈環境中測量性能的可靠性和準確性。在這兩個實驗中，所有測量值的誤差率都不超過10 %。在小鼠研究中，壁剪切應力和心脈衝波傳播速度成功地應用於小鼠頸動脈的分叉處。與野生型小鼠相比，載脂蛋白E基因敲除小鼠的頸動脈壁剪切應力和心脈衝波速度明顯增加。在載脂蛋白E基因敲除小鼠中，頸總動脈上方的時間平均壁剪切應力為1.89 ± 0.33 Pa，野生型小鼠為0.89 ± 0.27 Pa (p < 0.001)，並且載脂蛋白E基因敲除小鼠的心脈衝波速度為3.30 ± 0.45 m/s，野生型小鼠為2.03 ± 0.31 m/s (p < 0.001)。
本文提出了使用高頻超音系統同時測量壁剪切應力和心脈衝波速度的技術，並成功用於評估小鼠的頸動脈。

Cardiovascular diseases (CVDs) are the most common non-communicable diseases and take an estimated 17.8 million lives each year. The most common cause of cardiovascular disease is atherosclerosis at the early stage, and wall shear stress (WSS) is one of the causes of atherosclerosis. WSS is considered to be an important parameter in hemodynamics and affects the vascular endothelium. Endothelial cell dysfunction contributes to vascular homeostasis loss in atherosclerosis, resulting in abnormal measurements of pulse wave propagation. At present, the interactions in the development of atherosclerotic lesions are still considered to be complex and there are still many problems in measuring the wall shear stress and pulse wave velocity (PWV) in the animal study. Therefore, simultaneous acquisition of the WSS and PWV parameters in animal studies is necessary as a research tool for future understanding of disease development mechanisms.
In this study, WSS imaging and PW imaging based on the 40 MHz high-frequency ultrafast ultrasound vector Doppler processing were proposed to measure the mice's carotid artery and applied the temporal registration to solve the occurrence of aliasing. In the phantom experiments, we prepared steady flow experiments and pulsatile flow Experiments for verifying the reliability and accuracy of the measurement performance in a simulated mice carotid environment. In both experiments, the error rate of all measured values did not exceed 10 %. In in vivo study, the WSS, and PWV were successfully applied to the bifurcation of the mice's carotid artery. The carotid artery WSS and PWV were significantly increased in ApoE-knockout (ApoE KO) mice compared to the wild type (WT) mice. Time average WSS magnitude value over the anterior common carotid artery (CCAa) were 1.89 ± 0.33 Pa in ApoE KO mice and 0.89 ± 0.27 Pa in WT mice (p < 0.001), and carotid artery PWV were 3.30 ± 0.45 m/s in WT mice and 2.03 ± 0.31 m/s in ApoE KO mice (p < 0.001).
The technique of using a high-frequency ultrafast ultrasound system to measure the WSS and PWV simultaneously was proposed in this paper and successfully used to assess the mice's carotid artery.

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