Non-invasive detection and monitoring of bone strength in osteoporosis

骨质疏松症是一种骨密度降低导致骨折风险增加的疾病，最常见于髋部、脊柱和手腕。在我们老龄化的加拿大人口中，骨质疏松症的患病率正在迅速增加，并且对我们的医疗保健系统构成了重大负担。本研究将最新发展的三维成像技术（高分辨率外围定量计算机断层扫描；HR-pQCT）与有限元（FE）法相结合，开发了一种新的骨质疏松监测诊断成像技术。有限元法是工程设计和试验中常用的一种数值模拟技术，是估算复杂材料强度的理想方法。结合起来，这种新工具将允许对受试者特异性骨强度进行无创评估，这将代表着基于密度测量的临床评估方法的重大转变。它将提供第一种能够根据临床图像数据测量患者骨强度的工具。除了临床适用性外，这种结合成像和有限元建模的方法将使新的研究能够研究骨骼的生成和/或骨折，骨骼和骨髓相之间的相互作用（固液相互作用）以及营养物质和/或药物的运输。提出的工作将集中在三个目标上：(1)开发一种快速、有效的线性有限元建模方法，以便对骨微结构的HR-pQCT测量进行建模，以确定骨强度，并且比目前使用广泛可用的廉价计算硬件的方法快得多；(2)研究本构材料特性的结合

Osteoporosis is a disease of decreased bone density resulting in an increased risk of fracture, most often in the hip, spine and wrist. In our aging Canadian population, the prevalence of osteoporosis is rapidly increasing, and represents a significant burden on our health care system. This research develops a new diagnostic imaging technique for monitoring osteoporosis by combining a recently developed three-dimensional imaging technology (high-resolution peripheral quantitative computed tomography; HR-pQCT) with the finite element (FE) method to estimate bone strength. The FE method is a numerical simulation technique commonly used in engineering design and testing, and is ideal for estimated the strength of complex materials. Combined, this novel tool will allow non-invasive assessment of subject-specific bone strength, and this would represent a significant shift from the clinical assessment approach that is based on density measurements. It will provide the first tool to be able to measure a patients' bone strength based on clinical image data. In addition to clinical applicability, this combined imaging and FE modeling approach would enable new research to study how bone yields and/or fractures, the interaction between bone and marrow phases (solid-fluid interaction) and nutrient and/or drug transport. The proposed work will focus on three objectives: (1) To develop a fast, efficient linear FE modeling approach so that HR-pQCT measurements of bone microarchitecture can be modeled to determine bone strength, and to do so considerably faster than current methods using widely available inexpensive computing hardware; (2) To investigate incorporation of constitutive material properties for