Microscopic analysis of three-dimensional trabecular structure using X-ray and syncrotron radiation

1)有两种不同类型的抗骨质疏松剂;抗再吸收剂和骨形成剂。前一种药物的作用是保持骨小梁的连接性，而后者的作用是使卵巢切除大鼠的骨小梁变小。2）根据来自几项抗吸收药物临床试验的荟萃分析，这些临床试验着眼于椎骨骨折的相对风险与每项试验的骨矿物质密度（BMD）的平均变化，治疗的大部分效果是通过脊柱骨密度增加8%来解释的，这产生了41%的风险降低。然而，没有证据，也没有解释。有限元分析（FEA）表明，抗再吸收剂保持连接性的这种作用似乎增加了骨强度，但BMD略有增加。3）我们的micro-FEA系统经过验证，可评估骨质疏松大鼠模型中骨的机械性能，包括松质骨和皮质的个体性能。我们发现，每个组件的力学性能与各自的骨量，体积或结构有显着的关系。骨小梁显微结构与骨强度有显著相关性，骨小梁显微结构恶化的OVX骨，骨强度主要取决于皮质成分。4）SR-CT是一种描绘骨小梁表面、评价骨矿化和精确显示骨小梁结构的有用工具。我们可以使用取决于钙和碳之间的能量的不同质量衰减系数来可视化和量化钙密度。我们根据公式计算钙密度：CT值= mca/ro x rca+mc/ro x rc

1) There are two different types of anti-osteoporotic agents ; anti-resorptive agent and bone-formative agent. The effect of the former agent was shown to preserve trabecular connectivity, while that of the latter was to thicken trabeculae in the ovariectomized rats.2) According to the meta-analysis from several clinical trials of antiresorptive agents looking at the relative risk of vertebral fractures against the average change in bone mineral density (BMD) for each trial, most of the effect of treatment was explained by an 8% increase in spinal BMD, which produced a 41% risk reduction. However, there is no proofs nor explanations. Finite element analysis (FEA) demonstrated that this effect of anti-resorptive agent to preserve connectivity seemed to increase bone strength with small increase in BMD.3) Our micro-FEA system was validated to assess the mechanical properties of bone, including the individual properties of the spongiosa and cortex, in the osteoporotic rat model. We found that the mechanical property of each component had a significant relationship with the respective bone mass, volume or structure. While trabecular microstructure has a significant relationship with bone strength, in the OVX bone with deteriorated trabecular microstructure, the strength mainly depended on the cortical component.4) SR-CT seems to be a useful tool for delineating trabecular surfaces, evaluating bone mineralization, and for revealing precise trabecular structure. We could visualize and quantify the calcium density using the different mass attenuation coefficients depending on energy between calcium and carbon. We calculated the calcium density according to the formula : CT value= mca/ro x rca+mc/ro x rc