Research on Cross-Sectional Imaging of Elasticity around Atherosclerotic Plaque with Transcutaneous Ultrasound

经皮超声对动脉粥样硬化斑块周围弹性的断面成像研究

• 批准号: 10650400
• 负责人: KANAI Hiroshi
• 金额: $ 2.24万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650400/
• 关键词: atherosclerosis; medical ultrasonics; elasticity; phased tracking; noninvasive measurement; tissue characterization; atheroma; bio-rheology; 心筋症; リアルタイム計測; 心筋viability; 循環器系定量診断

The phased tracking method is unique in its extremely higher spatial and temporal resolution. This report shows the cross sectional image of the elasticity around the atherosclerotic plaque with this phase tracking method using transcutaneous ultrasound.The minimum value of the measurable velocity is 0.5 mm/s and the time interval, ΔT, of integration is 222 μs. In this condition, the lowest value of the change in thickness is found to be about 0.1μm in the measurements using a water tank. Such a minute change in thickness cannot be measured by CT, MRI, or standard ultrasonic diagnostic equipment.By presetting multiple points with equal intervals of 375 μm in the arterial wall at the R-wave of the ECG, and applying the above method to each point, the change in thickness in each layer between the succeeding points is determined. The change in thickness of each layer from that at the R-wave is then converted into color maps and displayed. By the proposed procedure described above, the elastic modulus E of the human carotid artery is noninvasively evaluated for the five layers along the ultrasonic beam.By modifying the method and system described above so that the elastic modulus of each local point in the arterial wall and the atherosclerotic plaque is determined by controlling the position of the ultrasonic beam. The results are then converted into another color map representing local elasticity in the cross sectional image. The regional elasticity is measured at each point along the ultrasonic beams at 30 positions along the axial direction of the artery. The resolution in the depth direction and axial direction is 375 μm and 0.98 mm, respectively. The atherosclerotic plaque has been characterized as the compliant material interior surrounded by much elastic material. With extrapolation of the results in an in vitro study, we interpreted the surrounding thin layer as the fibrous cap of the plaque.

相位跟踪方法的独特之处在于其极高的空间和时间分辨率。本文用经皮超声相位跟踪法显示了动脉粥样硬化斑块周围弹性的横断面图像。可测速度的最小值为0.5 mm/S，积分时间间隔ΔT为222μS。在这种情况下，用水箱测量厚度变化的最低值约为0.1μm。这种微小的厚度变化不能用CT、MRI或标准超声诊断设备来测量。通过在心电R波处的动脉壁上预先设置多个等间隔375μm的点，并对每个点应用上述方法，来确定后续点之间的每一层的厚度变化。然后，将每一层的厚度从R波处的变化转换成彩色图并显示。通过对上述方法和系统的改进，通过控制超声波束的位置来确定动脉壁各局部点和动脉粥样硬化斑块的弹性模数，从而无创地计算出人体颈动脉沿超声波束的五层结构的弹性系数E。然后将结果转换为代表横截面图像中的局部弹性的另一颜色图。在沿动脉轴向的30个位置沿超声波束的每个点测量局部弹性。深度方向分辨率为375μm，轴向分辨率为0.98 mm。动脉粥样硬化斑块的特征是内部被大量弹性材料包围的顺应性材料。通过外推体外研究的结果，我们将周围的薄层解释为斑块的纤维帽。

项目成果

H.Kanai,他3名: "Accuracy Evaluation in Ultrasonic-based Measurement of Microscopic Change in Thick-ness"Electronics Letters. 35. 949-950 (1999)

H. Kanai 等人：“基于超声波的厚度微观变化测量的精度评估”《电子快报》35. 949-950 (1999)。

Hiroshi Kanai, and Yoshiro Koiwa: "PARCORR-based Time-Dependent AR Spectrum Estimation of Heart Wall Vibrations" IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences. E82-A・4(印刷中). (1999)

Hiroshi Kanai 和 Yoshiro Koiwa：“基于 PARCORR 的心壁振动的时间相关 AR 频谱估计”IEICE 电子、通信和计算机科学基础知识汇刊 E82-A·4（出版中）。

長谷川英之,金井 浩,星宮 望,中鉢憲賢,小岩喜郎: "動脈壁の厚み変化波形の周波数解析" 日本音響学会誌. 54・7. 473-481 (1998)

Hideyuki Hasekawa、Hiroshi Kanai、Nozomu Hoshimiya、Kenken Chubachi、Yoshiro Koiwa：“动脉壁厚度变化波形的频率分析”日本声学学会杂志 54・7（1998）。

H.Kanai, Y.Koiwa, Y.Saito, I.Susukida, and M.Tanaka: "In vivo Measurement of Small Velocity Signals and Change in Thickness of the Heart Walls" Japanese Journal of Applied Physics. 38・5B(印刷中). (1999)

H.Kanai、Y.Koiwa、Y.Saito、I.Susukida 和 M.Tanaka：“小速度信号的体内测量和心壁厚度的变化”日本应用物理学杂志 38・5B（出版中） ））（1999）。

Hiroshi KANAI, Shigemitsu NAKAYA, Hideyuki HONDA, and Yoshiro KOIWA: "Noninvasive Estimation of Left-Ventricular End-Diastole Elasticity by Analyzing Heart Wall Vibrations"Electronics Letters. Vol. 35, No. 10. 765-766 (1999)

Hiroshi KANAI、Shigemitsu NAKAYA、Hideyuki HONDA 和 Yoshiro KOIWA：“通过分析心壁振动对左心室舒张末期弹性进行无创估计”电子快报。