High Frame Rate Vascular Ultrasound Innovations for Complex Flow Imaging

在人体动脉中呈现血流动力学的技术在检测血管异常方面非常有用。一个关键的应用领域是颈动脉粥样硬化的诊断，这是一种血管疾病，其特征是形成斑块，使向大脑供应血液的循环分支变窄。我的研究计划将寻求通过设计新的三维(3D)超声成像解决方案来寻求在血管诊断方面取得重大进展，该解决方案可以在脉搏周期的不同阶段检查主要动脉(如颈动脉)中复杂流动模式的时空演变。具体地说，我的团队将致力于： 1)设计高帧频3D复杂血流成像框架，实现动脉体积内复杂血流的时间分辨动态绘制(时间分辨率为亚毫秒级，远超典型的20-30帧/秒的视频显示速率)； 2)为系统硬件(阵列换能器、接口电子学)和实时计算(图形处理单元处理)制定新的解决方案，这是实际实现高帧频三维复杂流动成像所必需的； 3)设计基于流矢量分析(壁面剪切率、涡度和螺旋度的时空映射)的血流动力学参数可视化算法，以从复杂的流型中获得功能洞察力； 4)通过设计3D血流模型(例如动脉瘤和血管树模型)并进行一系列体外血流实验，分析我们的成像创新的实际效果。 我们提出的创新努力将带来首个此类非侵入性医学成像解决方案，该解决方案可以在护理点设置下以时间分辨的方式有效跟踪3D复杂血流动力学，而不使用电离辐射。它们将在促进临床医生对动脉粥样硬化等血管病理做出更知情的诊断方面发挥有利作用。反过来，血管病人将成为主要受益者；例如，对颈动脉粥样硬化的改进诊断有助于降低中风的发生率，在加拿大，中风每年导致1.4万人死亡。这项研究还将有利于培养加拿大生物医学工程研发人才库，加强加拿大在超声成像研发方面的核心能力，确立加拿大在该领域的全球领先地位。

Technologies that render flow dynamics in human arteries are highly useful in the detection of vascular abnormalities. One key application area is the diagnosis of carotid atherosclerosis, a vascular disease marked by the formation of plaques that narrow the circulatory branch supplying blood to the brain. My research program will seek to make significant advances in vascular diagnostics by engineering new three-dimensional (3D) ultrasound imaging solutions that can examine, over different phases of a pulsatile pulse cycle, the spatiotemporal evolution of complex flow patterns in major arteries such as the carotid. Specifically, my team will aim to: 1) Design a high-frame-rate 3D complex flow imaging framework to achieve time-resolved dynamic rendering of complex flow inside arterial volumes (sub-millisecond time resolution; well beyond the typical video display rate of 20-30 frames per second); 2) Formulate new solutions for system hardware (array transducer, interfacing electronics) and real-time computing (graphics processing unit processing) that are essential to practical realization of high-frame-rate 3D complex flow imaging; 3) Devise hemodynamic parameter visualization algorithms based on flow vector analysis (space-time mapping of wall shear rate, vorticity, and helicity) to derive functional insights from complex flow patterns; 4) Analyze the practical efficacy of our imaging innovations by designing 3D flow phantoms (e.g. models of aneurysms and vascular trees) and performing a series of flow experimentation in vitro. Our proposed innovation endeavors will lead to the first non-invasive medical imaging solutions of their kind that can effectively trace 3D complex hemodynamics in a time-resolved manner under point-of-care settings and without using ionizing radiation. They will play an enabling role in facilitating clinicians to make more informed diagnosis of vascular pathologies such as atherosclerosis. In turn, vascular patients will be the principal beneficiaries; for instance, improved diagnosis of carotid atherosclerosis can help reduce the incidence of stroke, which is responsible for 14,000 deaths per year in Canada. This research will also benefit the grooming of Canada's R&D talent pool in biomedical engineering and the strengthening of Canada's core competence in ultrasound imaging R&D, establishing Canada's position as a global leader in this field.