Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN, USA.
IEEE Trans Ultrason Ferroelectr Freq Control. 2011 Dec;58(12):2608-19. doi: 10.1109/TUFFC.2011.2124.
Shearwave dispersion ultrasound vibrometry (SDUV) is used to quantify both tissue shear elasticity and shear viscosity by evaluating dispersion of shear wave propagation speed over a certain bandwidth (50 to 500 Hz). The motivation for developing elasticity imaging techniques is the desire to diagnose disease processes. However, it is important to study the mechanical properties of healthy tissues; such data can enhance clinical knowledge and improve understanding of the mechanical properties of tissue. The purpose of this study is to evaluate the feasibility of using SDUV for in vitro measurements of renal cortex shear elasticity and shear viscosity in healthy swine kidneys. Eight excised kidneys from female pigs were used in these in vitro experiments and a battery of tests was performed to gain insight into the material proper ties of the renal cortex. In these 8 kidneys, the overall renal cortex elasticity and viscosity were 1.81 ± 0.17 kPa and 1.48 ± 0.49 Pa-s, respectively. In an analysis of the material properties over time after excision, there was not a statistically significant difference in shear elasticity over a 24-h period, but a statistically significant difference in shear viscosity was found. Homogeneity of the renal cortex was examined and it was found that shear elasticity and shear viscosity were statistically different within a kidney, suggesting global tissue inhomogeneity. In creases of more than 30% in shear elasticity and shear viscosity were observed after immersion in 10% formaldehyde. Finally, it was found that the renal cortex is rather anisotropic. Two values for shear elasticity and shear viscosity were measured depending on shear wave propagation direction. These various tests elucidated different aspects of the material properties and the structure of the ex vivo renal cortex.
剪切波频散超声振动测量法（SDUV）通过评估剪切波传播速度在一定带宽（50 至 500Hz）内的分散来定量评估组织剪切弹性和剪切粘性。开发弹性成像技术的动机是诊断疾病过程的愿望。然而，研究健康组织的力学性能也很重要；此类数据可以增强临床知识并提高对组织力学性能的理解。本研究旨在评估使用 SDUV 进行体外测量健康猪肾皮质剪切弹性和剪切粘性的可行性。在这些体外实验中使用了 8 个从雌性猪身上切除的肾脏，并进行了一系列测试以深入了解肾皮质的材料特性。在这 8 个肾脏中，整体肾皮质弹性和粘性分别为 1.81±0.17kPa 和 1.48±0.49Pa-s。在切除后随时间进行的材料特性分析中，在 24 小时内剪切弹性没有统计学上的显著差异，但剪切粘性存在统计学差异。检查了肾皮质的均匀性，发现肾内剪切弹性和剪切粘性存在统计学差异，表明整体组织不均匀。在浸入 10%甲醛后，剪切弹性和剪切粘性分别观察到超过 30%的增加。最后，发现肾皮质具有各向异性。根据剪切波传播方向测量了剪切弹性和剪切粘性的两个值。这些各种测试阐明了离体肾皮质的材料特性和结构的不同方面。
