Graduate School of Engineering, Tohoku University, Sendai, Japan.
Graduate School of Engineering, Tohoku University, Sendai, Japan; Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan.
Ultrasound Med Biol. 2023 Mar;49(3):875-888. doi: 10.1016/j.ultrasmedbio.2022.11.014. Epub 2023 Jan 7.
Quantification of the dynamics of the carotid artery wall is useful in evaluating arteriosclerosis and atherosclerosis. As the carotid artery wall moves not only in the radial direction but also in the longitudinal direction, longitudinal movement should be considered in the analysis of the dynamic properties of the carotid artery wall. In this study, we propose a "lateral M-mode" method for visualizing the longitudinal movement of the intima-media complex (IMC). For the lateral M-mode, we set the target line in the longitudinal direction along the IMC and visualize the signals on the target line frame-by-frame by correcting the position of the target line along the radial displacement estimated by the phased tracking method. Differentiating the envelope signals between consecutive ultrasound beams was effective in visualizing the lateral movement of the IMC. The precision of the longitudinal displacement of the IMC estimated using the conventional block-matching method was validated by comparing it with the lateral M-mode. Because the conventional M-mode sequence plays an important role in evaluation of the dynamics of various tissues, the proposed "lateral M-mode" contributes to a detailed understanding of vascular dynamics and the development of diagnostic methods for vascular diseases.
量化颈动脉壁的动力学变化有助于评估动脉硬化和动脉粥样硬化。由于颈动脉壁不仅在径向方向上移动，而且在纵向方向上移动，因此在分析颈动脉壁的动态特性时应考虑纵向运动。在这项研究中，我们提出了一种用于可视化内中膜复合体（IMC）纵向运动的“横向 M 型”方法。对于横向 M 型，我们在纵向方向上设置目标线，通过相位跟踪方法估计的径向位移来校正目标线的位置，逐帧可视化目标线上的信号。区分连续超声束之间的包络信号对于可视化 IMC 的横向运动非常有效。通过与横向 M 型进行比较，验证了使用传统的块匹配方法估计的 IMC 纵向位移的精度。由于常规 M 型序列在评估各种组织的动力学方面起着重要作用，因此所提出的“横向 M 型”有助于更详细地了解血管动力学和血管疾病的诊断方法。
