Soleimani Effat, Mokhtari-Dizaji Manijhe, Fatouraee Nasser, Saberi Hazhir
Department of Medical Physics, Tarbiat Modares University, Tehran, Iran.
Department of Medical Engineering, AmirKabir University of Technology, Tehran, Iran.
Ultrasonography. 2021 Jul;40(3):428-441. doi: 10.14366/usg.20131. Epub 2021 Jan 5.
This study investigated the accuracy of models reconstructed from ultrasound image processing by comparing the radial displacement waveforms of a subject-specific artery model and evaluated stress changes in the proximal shoulder, throat, and distal shoulder of the plaques depending on the degree of carotid artery stenosis.
Three groups of subjects (healthy and with less than 50% or more carotid stenosis) were evaluated with ultrasonography. Two-dimensional transverse imaging of the common carotid artery was performed to reconstruct the geometry. A longitudinal view of the same region was recorded to extract the Kelvin viscoelastic model parameters. The pulse pressure waveform and the effective pressure of perivascular tissue were loaded onto the internal and external walls of the model. Effective, circumferential, and principal stresses applied to the plaque throat, proximal shoulder, and distal shoulder in the transverse planes were extracted.
The radial displacement waveforms of the model were closely correlated with those of image processing in all three groups. The mean of the effective, circumferential, and principal stresses of the healthy arteries were 15.01±4.93, 12.97±5.07, and 12.39±2.86 kPa, respectively. As stenosis increased from mild to significant, the mean values of the effective, circumferential, and first principal stresses increased significantly (97%, 74%, and 103% at the plaque throat, respectively) (P<0.05). The minimum effective stress was at the lipid pool. The effective stress in calcified areas was higher than in other parts of the artery wall.
This model can discriminate differences in stresses applied to mildly and severely stenotic plaques.
本研究通过比较特定受试者动脉模型的径向位移波形，研究了从超声图像处理重建的模型的准确性，并评估了根据颈动脉狭窄程度不同，斑块近端肩部、喉部和远端肩部的应力变化。
对三组受试者（健康者以及颈动脉狭窄程度小于50%或大于50%者）进行超声检查。对颈总动脉进行二维横向成像以重建几何形状。记录同一区域的纵向视图以提取开尔文粘弹性模型参数。将脉压波形和血管周围组织的有效压力加载到模型的内壁和外壁上。提取在横向平面中施加到斑块喉部、近端肩部和远端肩部的有效应力、周向应力和主应力。
在所有三组中，模型的径向位移波形与图像处理的波形密切相关。健康动脉的有效应力、周向应力和主应力的平均值分别为15.01±4.93、12.97±5.07和12.39±2.86kPa。随着狭窄程度从轻度增加到重度，有效应力、周向应力和第一主应力的平均值显著增加（在斑块喉部分别增加97%、74%和103%）（P<0.05）。最小有效应力位于脂质池处。钙化区域的有效应力高于动脉壁的其他部分。
该模型可以区分轻度和重度狭窄斑块所受应力的差异。
