Study on visualization of defect of internal elastic lamina of arterial wall for diagnosis of very early-stage atherosclerosis

在动脉粥样硬化早期，测量颈动脉壁微小表面粗糙度对检测内皮损伤有重要意义。在常规超声成像中，b模图像的轴向分辨率取决于超声波长为150 μm，频率为10 MHz。因此，传统的b型超声图像无法测量动脉粥样硬化早期引起的表面粗糙度，因为粗糙度为10-20 μm。我们利用颈动脉壁的横向运动，通过对接收到的超声信号进行块匹配来估计，实现了对这种微小表面轮廓的经皮准确估计。实验结果表明，该方法能够测量出直径约为10 μm的小表面轮廓。此外，对3名健康受试者（24岁、23岁和23岁男性）进行了10-50 μm颈动脉壁表面粗糙度的可重复性测量。

It would be useful to measure the minute surface roughness of the carotid arterial wall to detect the endothelial damage in the early-stage of atherosclerosis. In conventional ultrasonography, the axial resolution of a B-mode image depends on the ultrasonic wavelength of 150 μm at 10 MHz. Therefore, the surface roughness caused by atherosclerosis in an early stage cannot be measured using a conventional B-mode image obtained by ultrasonography because the roughness is10-20 μm. We have realized accurate transcutaneous estimation of such a minute surface profile using the lateral motion of the carotid arterial wall, which is estimated by block matching of received ultrasonic signals. The proposed method was proved to be able to measure minute surface profile of about 10 μm by measuring a phantom, which had a saw tooth profile on its surface. Furthermore, the surface roughness of the carotid arterial walls of 10-50 μm were measured reproducibly for three healthy subjects (24-, 23-, and 23-year-old males).