In vitro acoustic waves propagation in human and bovine cancellous bone
In vitro acoustic waves propagation in human and bovine cancellous bone
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DOI：
10.1359/jbmr.2003.18.10.1803
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发表时间：
2003-10-01
影响因子：
6.2
通讯作者：
Meunier, A
中科院分区：
文献类型：
--
作者：
Cardoso, L;Teboul, F;Meunier, A
松质骨的声学行为与其复杂的孔弹性性质有关。牛松质骨和人松质骨中均存在两种纵向传播模式。如果不考虑这两种波的存在，可能会导致材料表征的不准确。前言：声波传播是目前常用的一种非破坏性松质骨表征方法。然而，波在这种材料中的传播可能会受到其固有的多孔弹性性质的流固相互作用的影响，从而产生两种不同的纵波。这一现象已在以往的研究中得到证实，并与比奥特的理论相一致。本文的目的是将这些发现推广到人的松质骨中，并对这两种波进行深入的研究。材料和方法：采用浸入式声传输法对60个人和14个牛松质骨立方体标本进行了三个不同方向的体外测试。最初的程序是用来量化每个波的速度和衰减特性的。在衰减方面，为每个波定义了一个修正的宽带超声衰减(BUA)，它描述了频率依赖性衰减的变化率(FDUA)。快波速度与孔隙度呈线性负相关(1500-2300m/S，R-2=0.44，p<；10(-3))，而慢波速度表现出两种不同的特征：(1)第一组数据明显依赖于孔隙度(1150-1450m/S，R2=0.26，p<；10(-3))；(2)第二组与孔隙度无关。快波FDUA(20-140dB/cmMHz)表现出抛物线行为，其最大孔隙率为75%(二级关系R-2=0.41，p<；10(-3))，而慢波FDUA(15-40db/cmMHz；R-2=0.15，p<；10(-2))呈现出正的线性行为。我们的数据表明，在某些情况下，慢波的幅度比快波的幅度大得多。因此，在使用包含简单阈值检测的测量系统时应小心，因为快波可能仍未被检测到。此外，如果不考虑这两种波的存在，可能会导致对松质骨物理特性的不准确量化。
The acoustic behavior of cancellous bone with regard to its complex poroelastic nature has been investigated. The existence of two longitudinal modes of propagation is demonstrated in both bovine and human cancellous bone. Failure to take into account the presence of these two waves may result in inaccurate material characterization.Introduction: Acoustic wave propagation is now a commonly used nondestructive method for cancellous bone characterization. However, wave propagation in this material may be affected by fluid-solid interactions inherent to its poroelastic nature, resulting in two different longitudinal waves. This phenomenon has been demonstrated in previous studies and is in agreement with Biot's theory. The purpose of this paper is to extend these findings to human trabecular bone and to thoroughly investigate these two waves.Materials and Methods: Sixty human and 14 bovine cancellous bone cubic specimens were tested in vitro in three different directions using an immersion acoustic transmission method. Original procedures were developed to quantify both velocity and attenuation characteristics of each wave. In term of attenuation, a modified broadband ultrasound attenuation (BUA), describing the rate of change of the frequency-dependent attenuation, was defined for each wave (FDUA).Results: Both waves were identified in most of the specimens. The fast wave velocities demonstrated a negative linear correlation with porosity (1500-2300 m/s, R-2 = 0.44, p < 10(-3)), whereas the slow wave velocities exhibited two different behaviors: (1) a first set of data clearly dependent on porosity showing a positive linear correlation (1150-1450 m/s, R-2 = 0.26, p < 10(-3)) and (2) a second group independent on porosity. The fast wave FDUA (20-140 dB/cmMHz) showed a parabolic behavior and reached a maximum for 75% porosity (second degree relationship R-2 = 0.41, p < 10(-3)), whereas a positive linear behavior was observed for the slow wave FDUA (15-40 dB/cmMHz; R-2 = 0.15, p < 10(-2)).Conclusions: Existence of two wave propagation modes were demonstrated in human cancellous bone. Our data suggest that, in some cases, the amplitude of the slow wave is much larger than the amplitude of the fast wave. For this reason, care should be taken when using measurement systems that incorporate simple threshold detection because the fast wave could remain undetected. Moreover, failure to consider the presence of these two waves could result in an inaccurate quantification of cancellous bone physical properties.