Choi Gilwoo, Cheng Christopher P, Wilson Nathan M, Taylor Charles A
Department of Mechanical Engineering, Stanford University, Stanford, CA 94305-5431, USA.
Ann Biomed Eng. 2009 Jan;37(1):14-33. doi: 10.1007/s10439-008-9590-0. Epub 2008 Nov 11.
The knowledge of dynamic changes in the vascular system has become increasingly important in ensuring the safety and efficacy of endovascular devices. We developed new methods for quantifying in vivo three-dimensional (3D) arterial deformation due to pulsatile and nonpulsatile forces. A two-dimensional threshold segmentation technique combined with a level set method enabled calculation of the consistent centroid of the cross-sectional vessel lumen, whereas an optimal Fourier smoothing technique was developed to eliminate spurious irregularities of the centerline connecting the centroids. Longitudinal strain and novel metrics for axial twist and curvature change were utilized to characterize 3D deformations of the abdominal aorta, common iliac artery, and superficial femoral artery (SFA) due to musculoskeletal motion and deformations of the coronary artery due to cardiac pulsatile motion. These illustrative applications show the significance of each deformation metric, revealing significant longitudinal strain and axial twist in the SFA and coronary artery, and pronounced changes in vessel curvature in the coronary artery and in the inferior region of the SFA. The proposed methods may aid in designing preclinical tests aimed at replicating dynamic in vivo conditions in the arterial tree for the purpose of developing more durable endovascular devices including stents and stent grafts.
了解血管系统的动态变化对于确保血管内装置的安全性和有效性变得越来越重要。我们开发了新的方法来量化由于脉动和非脉动力量引起的体内三维（3D）动脉变形。一种二维阈值分割技术与水平集方法相结合，能够计算横截面血管腔的一致质心，而一种最优傅里叶平滑技术被开发出来以消除连接质心的中心线的虚假不规则性。纵向应变以及轴向扭转和曲率变化的新指标被用于表征腹主动脉、髂总动脉和股浅动脉（SFA）由于肌肉骨骼运动引起的3D变形，以及冠状动脉由于心脏脉动运动引起的变形。这些示例应用展示了每个变形指标的重要性，揭示了SFA和冠状动脉中显著的纵向应变和轴向扭转，以及冠状动脉和SFA下部区域血管曲率的明显变化。所提出的方法可能有助于设计临床前测试，旨在为开发包括支架和支架移植物在内的更耐用的血管内装置而复制动脉树中的动态体内条件。
