PDF(Pubmed)
Abstract：
In vivo studies on association between wall shear stress (WSS) and intracranial plaque are deficient. Based on the three-dimensional T1-weighted high-resolution magnetic resonance imaging (3DT1 HR-MRI) data of patients with low-grade stenotic (<50%) atherosclerotic middle cerebral artery (MCA) and subjects with normal MCA, we built a three-dimensional reconstructed WSS model by computational fluid dynamics (CFD) technique. Three-dimensional registration of the CFD model to the HR-MRI was performed with projections based on the resolution and thickness of the images. The relationships between the WSS at each side of the vessel wall and plaque location were analyzed. A total of 94 MCA plaques from 43 patients and 50 normal MCAs were analyzed. In the normal MCAs, WSS was lower at the ventral-inferior wall than at the dorsal-superior wall (proximal segment, p < 0.001; middle segment, p < 0.001) and lower at the inner wall than at the outer wall of the MCA curve (p < 0.001). In atherosclerotic MCAs, similar low WSS regions were observed where plaques developed. The WSS ratio of the ventral-inferior wall to the dorsal-superior wall in atherosclerotic MCAs was lower than that in normal MCAs (p = 0.002). The WSSinner-outer ratio in atherosclerotic MCAs was lower than that in normal MCAs (p = 0.002). Low WSS was associated with MCA atherosclerosis formation and occurred mainly at the ventral-inferior wall, which was anatomically opposite the orifices of penetrating arteries, and at the inner wall of the MCA curve. Overall, the results were well consistent with the low WSS theory in atherosclerosis formation. The reconstructed WSS model is a promising novel method for assessing an individualized vascular profile once validated by further studies.
摘要：
关于壁切应力（WSS）与颅内斑块之间关联的体内研究不足。根据低度狭窄(<50%)动脉粥样硬化大脑中动脉(MCA)患者和MCA正常受试者的三维T1加权高分辨率磁共振成像(3DT1HR-MRI)数据,利用计算流体动力学(CFD)技术建立了WSS三维重建模型。CFD模型与HR-MRI的三维配准是根据图像的分辨率和厚度进行投影的。分析血管壁每侧的WSS与斑块位置之间的关系。分析了来自43例患者和50例正常MCA的总共94个MCA斑块。在正常的MCA中，腹下壁的WSS低于背上壁（近端，p<0.001；中段，p<0.001），并且在MCA曲线的内壁低于外壁（p<0.001）。在动脉粥样硬化MCAs中，在斑块发育的地方观察到相似的低WSS区域。动脉粥样硬化MCAs中腹下壁与背上壁的WSS比低于正常MCAs（p=0.002）。动脉粥样硬化MCAs的WSSinner-outer比值低于正常MCAs（p=0.002）。低WSS与MCA动脉粥样硬化形成有关，主要发生在腹下壁，它在解剖学上与穿透动脉的孔口相对，和MCA曲线的内壁。总的来说,结果与动脉粥样硬化形成的低WSS理论非常吻合.一旦通过进一步的研究验证，重建的WSS模型是评估个性化血管轮廓的一种有前途的新颖方法。
