MR评估在体血管壁切应力的方法探讨

In vivo MR evaluation of the vessel wall shear stress in the common carotid artery

目的研究一种临床适用的MR技术在体无创性评估颈总动脉血管壁切应力（WSS）的方法。方法选取1名健康志愿者，对其右侧颈总动脉行相位对比法MR血流定量扫描，应用三维抛物面（3DP）模型函数拟合方法，结合图像后处理技术，计算局部WSS，获取颈总动脉的血管横截面积、平均血流速度、最大速度及瞬时血流率等血流动力学参数，综合评估颈总动脉的血流动力学状态。结果颈总动脉局部WSS值范围为（0．75±0．41）N／m^2；平均血流速度为（23．4±12．0）cm／s，血管横截面积为（32．2±2．9）mm^2；血流率为（7．8±4．6）ml／s。结论MR血流定量技术结合3DP模型方法可以对颈动脉局部WSS大小、分布和变化进行评估。

Objective To apply a non-invasive and feasible method for the quantification of local wall shear stress （WSS） in vivo using magnetic resonance imaging. Methods The right common carotid artery of a young healthy male volunteer was examined using cine phase-contrast MR sequence. The crosssectional area, average flow velocity, maximum velocity and flow rate were obtained. Three dimensional paraboloid model was applied to measure WSS value at common carotid artery. Results The mean/peak WSS was （0. 75 ± 0. 41 ） N/m^2 for the common carotid artery; The mean （range） velocity was （23.4 ±12.0） era/s; The mean （range） luminal vessel area was （32.2±2.9） mm^2; The blood flow rate was （7. 8 ±4. 6） ml/s; Conclusion WSS＇s magnitude, distribution and changes can be determined by MR imaging combining with the three-dimensional paraboloid method.