Instituto de Física de Líquidos y Sistemas Biológicos (IFLYSIB-CCT La Plata-CONICET), Calle 59 No 789, B1900BTE La Plata, Argentina.
Med Eng Phys. 2013 Aug;35(8):1173-80. doi: 10.1016/j.medengphy.2012.12.014. Epub 2013 Jan 23.
In this work, two-dimensional simulations of the microwave dielectric properties of models with ellipses and realistic models of trabecular bone tissue are performed. In these simulations, finite difference time domain methodology has been applied to simulate two-phase structures containing inclusions. The results presented here show that the micro-structure is an important factor in the effective dielectric properties of trabecular bone. We consider the feasibility of using the dielectric behaviour of bone tissue to be an indicator of bone health. The frequency used was 950 MHz. It was found that the dielectric properties can be used as an estimate of the degree of anisotropy of the micro-structure of the trabecular tissue. Conductivity appears to be the most sensitive parameter in this respect. Models with ellipse shaped-inclusions are also tested to study their application to modelling bone tissue. Models with ellipses that had an aspect ratio of a/b=1.5 showed relatively good agreement when compared with realistic models of bone tissue. According to the results presented here, the anisotropy of trabecular bone must be accounted for when measuring its dielectric properties using microwave imaging.
在这项工作中,对具有椭圆体的模型和小梁骨组织的实际模型的微波介电特性进行了二维模拟。在这些模拟中,应用了时域有限差分方法来模拟包含夹杂的两相结构。这里呈现的结果表明,微结构是小梁骨有效介电特性的一个重要因素。我们考虑使用骨组织的介电行为作为骨健康的指标的可行性。所使用的频率为 950 MHz。发现介电特性可以用作小梁组织微结构各向异性程度的估计。在这方面,电导率似乎是最敏感的参数。还测试了具有椭圆形夹杂的模型,以研究它们在模拟骨组织中的应用。当与骨组织的实际模型相比时,纵横比为 a/b=1.5 的椭圆形夹杂模型显示出相对较好的一致性。根据这里呈现的结果,在使用微波成象测量小梁骨的介电特性时,必须考虑其各向异性。