Non-invasive assessment of bone strength

骨是一种适应性很强的组织，可以在疾病或损伤后迅速重塑。骨的三维（3D）微观结构是理解骨力学的关键，计算机断层扫描（CT）的进步，加上定制的有限元（FE）分析方法，允许分析骨重塑信号如何在复杂结构中分布。自2002年以来，我的实验室在高效和准确的计算建模方面取得了重大进展。这带来了巨大的机会，通过整合技术和发展新的计算方法来推进我们对骨适应机制的理解。继续我的研究计划的长期目标，下一阶段将利用新的纵向数据集来建立各种情况下骨适应的基本机制。它将时间序列图像数据分析与有限元建模相结合，直接将骨骼的生物适应与其机械和生理功能联系起来。新的方向还包括开发多模态成像方法，将磁共振成像（MRI）和CT相结合，以便探索关键生物组织（特别是软骨和骨）的功能相互作用。******我下一阶段的研究计划有三个主要目标。首先，建立一个骨骼适应的机制模型，该模型采用以下受试者的实验纵向数据：(1)暴露于微重力环境6个月（国际空间站宇航员），(2)通过我们基于人群的研究代表正常衰老，(3)正在接受实验性治疗以增强其骨骼强度。将患者特异性FE模型与测量的局部骨微结构变化相结合，为了解骨适应机制提供了独特的基础。其次，推进高通量图像处理，采用允许分析代表多年数据集的大量3D图像数据的策略。个体之间骨适应的自然变异性很大，需要高通量方法来最大限度地进行系列观察。第三个目标是建立高分辨率整合软硬组织测量的方法，以便建立代表关节综合生物力学模型的综合有限元模型，以研究组织相互作用。******总体而言，本研究计划使用先进的成像和高性能的有限元建模来建立组织适应的机制模型，并将其应用于通过我实验室最近的几项研究获得的大型丰富数据集。这种方法为理解骨适应机制提供了重要的生物医学工程贡献。

Bone is a remarkably adaptive tissue that can rapidly remodel as a result of disease or injury. The three-dimensional (3D) microstructure of bone is key to understanding bone mechanics, and advancements of computed tomography (CT), coupled with customized finite element (FE) analysis methods, permit the analysis of how bone remodeling signals are distributed through the complex structure. Since 2002, my lab has made significant strides towards efficient and accurate computational modeling. This leads to enormous opportunities to advance our understandings of the mechanisms of bone adaptation through integration of technologies and the development of new computational approaches. Continuing with the long-term objective of my research program, this next phase will utilize novel longitudinal datasets to establish the fundamental mechanisms of bone adaptation under a variety of scenarios. It will couple analysis of time-series image data with FE modeling to directly link biological adaptations of bone to its mechanical and physiological functions. New directions also include developing multi-modal imaging approaches that integrate magnetic resonance imaging (MRI) and CT so that the functional interaction of key biological tissues, specifically cartilage and bone, can be explored. ******There are three main objectives of the next phase of my research program. First, establish a mechanistic model of bone adaptation that takes experimental longitudinal data of subjects who have (i) been exposed to microgravity for periods of six months (International Space Station astronauts), (ii) represent normal aging through our population-based study, and (iii) are undergoing experimental therapies to augment their bone strength. Coupling patient-specific FE models with measured local changes to bone microarchitecture provides a unique basis to learn about the mechanisms of bone adaptation. Second, advance high-throughput image processing, with the strategy to allow analysis of large volumes of 3D image data representing multi-year datasets. The natural variability of bone adaptation among individuals is large, and necessitates high-throughput approaches to maximum the number of serial observations. The third objective establishes methods to integrate hard and soft tissue measurements at high resolution so that comprehensive FE models can be developed that represent integrated biomechanical models of joints to study the tissue interactions. ******Overall, this research program uses advanced imaging and high-performance FE modeling to establish mechanistic models of tissue adaptation, and applies it to large, rich datasets that have been acquired through several recent studies in my lab. This approach provides an important biomedical engineering contribution toward understanding mechanisms of bone adaptation.