Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA.
J Biomech. 2013 Jul 26;46(11):1866-74. doi: 10.1016/j.jbiomech.2013.04.019. Epub 2013 Jun 12.
The aortic stiffness has been found to be a useful independent indicator of several cardiovascular diseases such as hypertension and aneurysms. Existing methods to estimate the aortic stiffness are either invasive, e.g. catheterization, or yield average global measurements which could be inaccurate, e.g., tonometry. Alternatively, the aortic pulse wave velocity (PWV) has been shown to be a reliable marker for estimating the wall stiffness based on the Moens-Korteweg (M-K) formulation. Pulse Wave Imaging (PWI) is a relatively new, ultrasound-based imaging method for noninvasive and regional estimation of PWV. The present study aims at showing the application of PWI in obtaining localized wall mechanical properties by making PWV measurements on several adjacent locations along the ascending thoracic to the suprarenal abdominal aortic trunk in its intact vessel form. The PWV estimates were used to calculate the regional wall modulus based on the M-K relationship and were compared against conventional mechanical testing. The findings indicated that for the anisotropic aortic wall, the PWI estimates of the modulus are smaller than the circumferential modulus by an average of -32.22% and larger than the longitudinal modulus by an average of 25.83%. Ongoing work is focused on the in vivo applications of PWI in normal and pathological aortas with future implications in the clinical applications of the technique.
主动脉僵硬度已被发现是多种心血管疾病（如高血压和动脉瘤）的一个有用的独立指标。现有的估计主动脉僵硬度的方法要么具有侵入性，例如导管插入术，要么只能得出平均的整体测量值，这可能不够准确，例如，张力测量法。或者，主动脉脉搏波速度（PWV）已被证明是一种可靠的标志物，可根据 Moens-Korteweg（M-K）公式来估计壁的僵硬度。脉冲波成像（PWI）是一种相对较新的基于超声的成像方法，用于非侵入性和区域性估计 PWV。本研究旨在展示 PWI 在获取局部壁力学特性方面的应用，即在完整的血管形式下，对胸升主动脉到肾上腹主动脉干的几个相邻部位进行 PWV 测量。PWV 估计值用于根据 M-K 关系计算局部壁模量，并与传统的机械测试进行比较。研究结果表明，对于各向异性的主动脉壁，PWI 估计的模量比周向模量小平均 -32.22%，比纵向模量大平均 25.83%。目前正在进行 PWI 在正常和病理性主动脉中的体内应用研究，为该技术的临床应用提供了未来的研究方向。
