Vos Hendrik J, van Dalen Bas M, Heinonen Ilkka, Bosch Johan G, Sorop Oana, Duncker Dirk J, van der Steen Antonius F W, de Jong Nico
Biomedical Engineering, Erasmus MC, Rotterdam, The Netherlands; Acoustical Wavefield Imaging, Delft University of Technology, Delft, The Netherlands.
Cardiology, Erasmus MC, Rotterdam, The Netherlands.
Ultrasound Med Biol. 2017 Apr;43(4):753-764. doi: 10.1016/j.ultrasmedbio.2016.11.015. Epub 2017 Jan 5.
Cardiac muscle stiffness can potentially be estimated non-invasively with shear wave elastography. Shear waves are present on the septal wall after mitral and aortic valve closure, thus providing an opportunity to assess stiffness in early systole and early diastole. We report on the shear wave recordings of 22 minipigs with high-frame-rate echocardiography. The waves were captured with 4000 frames/s using a programmable commercial ultrasound machine. The wave pattern was extracted from the data through a local tissue velocity estimator based on one-lag autocorrelation. The wave propagation velocity was determined with a normalized Radon transform, resulting in median wave propagation velocities of 2.2 m/s after mitral valve closure and 4.2 m/s after aortic valve closure. Overall the velocities ranged between 0.8 and 6.3 m/s in a 95% confidence interval. By dispersion analysis we found that the propagation velocity only mildly increased with shear wave frequency.
心肌僵硬度有可能通过剪切波弹性成像技术进行无创估计。在二尖瓣和主动脉瓣关闭后，间隔壁上会出现剪切波，从而提供了在收缩早期和舒张早期评估僵硬度的机会。我们报告了22只小型猪的高帧率超声心动图剪切波记录情况。使用可编程商用超声机器以4000帧/秒的速度捕捉这些波。通过基于单滞后自相关的局部组织速度估计器从数据中提取波型。用归一化拉东变换确定波传播速度，结果显示二尖瓣关闭后波传播速度的中位数为2.2米/秒，主动脉瓣关闭后为4.2米/秒。总体而言，在95%置信区间内，速度范围为0.8至6.3米/秒。通过色散分析我们发现，传播速度仅随剪切波频率略有增加。
