Pulse wave imaging (PWI) is an ultrasound imaging modality that estimates the wall stiffness of an imaged arterial segment by tracking the pulse wave propagation. The aim of the present study is to integrate PWI with vector flow imaging, enabling simultaneous and co-localized mapping of vessel wall mechanical properties and 2-D flow patterns. Two vector flow imaging techniques were implemented using the PWI acquisition sequence: 1) multiangle vector Doppler and 2) a cross-correlation-based vector flow imaging (CC VFI) method. The two vector flow imaging techniques were evaluated in vitro using a vessel phantom with an embedded plaque, along with spatially registered fluid structure interaction (FSI) simulations with the same geometry and inlet flow as the phantom setup. The flow magnitude and vector direction obtained through simulations and phantom experiments were compared in a prestenotic and stenotic segment of the phantom and at five different time frames. In most comparisons, CC VFI provided significantly lower bias or precision than the vector Doppler method ( ${p} < {0.05}$ ) indicating better performance. In addition, the proposed technique was applied to the carotid arteries of nonatherosclerotic subjects of different ages to investigate the relationship between PWI-derived compliance of the arterial wall and flow velocity in vivo . Spearman’s rank-order test revealed positive correlation between compliance and peak flow velocity magnitude ( ${r}_{s} = {0.90}$ and ${p} < {0.001}$ ), while significantly lower compliance ( ${p} < {0.01}$ ) and lower peak flow velocity magnitude ( ${p} < {0.001}$ ) were determined in older (54–73 y.o.) compared with young (24–32 y.o.) subjects. Finally, initial feasibility was shown in an atherosclerotic common carotid artery in vivo . The proposed imaging modality successfully provided information on blood flow patterns and arterial wall stiffness and is expected to provide additional insight in studying carotid artery biomechanics, as well as aid in carotid artery disease diagnosis and monitoring.

中文翻译：

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脉冲波成像与矢量流映射相结合：幻影、模拟和 体内 学习

脉搏波成像 (PWI) 是一种超声成像方式，它通过跟踪脉搏波传播来估计成像动脉段的壁硬度。本研究的目的是将 PWI 与矢量流成像相结合，实现血管壁机械特性和二维流动模式的同步和共定位映射。使用 PWI 采集序列实现了两种矢量流成像技术：1) 多角度矢量多普勒和 2) 基于互相关的矢量流成像 (CC VFI) 方法。评估了两种矢量流成像技术体外使用带有嵌入斑块的血管模型，以及具有与模型设置相同的几何形状和入口流量的空间注册流体结构相互作用 (FSI) 模拟。通过模拟和体模实验获得的流量大小和矢量方向在体模的前狭窄段和狭窄段以及五个不同的时间范围内进行了比较。在大多数比较中，CC VFI 提供的偏差或精度明显低于矢量多普勒方法（ ${p} < {0.05}$ ) 表示更好的性能。此外，将所提出的技术应用于不同年龄非动脉粥样硬化受试者的颈动脉，以研究 PWI 衍生的动脉壁顺应性与流速之间的关系体内 . Spearman 的排序检验显示顺应性和峰值流速大小之间呈正相关（ ${r}_{s} = {0.90}$ 和 ${p} < {0.001}$ )，而依从性显着降低 ( ${p} < {0.01}$ ) 和较低的峰值流速幅度 ( ${p} < {0.001}$ ) 是在老年 (54-73 岁) 与年轻 (24-32 岁) 受试者中确定的。最后，在动脉粥样硬化的颈总动脉中显示了初步可行性体内 . 所提议的成像方式成功地提供了关于血流模式和动脉壁硬度的信息，并有望为研究颈动脉生物力学提供额外的见解，并有助于颈动脉疾病的诊断和监测。