STRUCTURAL ANALYSIS OF HIP BONE MINERAL IMAGE DATA

骨骼结构强度的降低是 老年人髋部骨折。 骨矿物质 分析被广泛用于评估断裂倾向， 易感人群，常规分析不足以 歧视那些有风险的人。 我们开发了一种替代方案 技术的基础上，单平面弯曲应力分析的 股骨颈，单腿站立。 工作不同于 沿着这些路线的以前的努力，因为它使用获得的数据 通过广泛可用的常规骨矿物质扫描仪系统。 此外，股骨颈的必要结构特性 直接从数字骨矿物质图像数据计算， 一个简单的用户交互程序。 除了 结构几何形状、强度指标（包括差异） 在加载和材料强度的年龄变化，也是 计算。 初步工作表明， 可以可靠地获得的方法和强度估计， 尸体股骨与实验测量的 强度比传统的骨矿物质密度。 这 调查将旨在确定内在的 该方法的物理和生物力学限制，以及 将其敏感性和选择性与传统骨进行比较 矿物分析，在病人和尸体标本。 物理限制将与计算机模型进行检查， 扫描仪系统，包括系统几何形状、采样 考虑因素、源发射光谱和组织衰减 特性. 第二，对患者进行全面调查 定位误差的几何测量将进行 一个真实的臀部幻影 第三， 单平面弯曲应力分析将通过 使用髋关节图像数据与有限元分析进行比较。 这些努力的结果将用于完善 临床实施的方法。 应用于患者 人群将开始检查对侧 髋关节急性退行性骨折受试者。 在一个更大 规模的努力，髋骨矿物质数据，从几个无关，对- 正在进行的骨质疏松症研究将提供给髋关节 强度分析 这些研究包括： 巴尔的摩老龄化纵向样本，受试者来自两个 绝经后妇女在不同条件下的研究 治疗方案，以及研究的帕拉和四肢瘫痪受试者 或者长期瘫痪

Reduction of skeletal structural strength is a prime cause of osteoporotic hip fractures among the elderly. While bone mineral analysis is widely used in assessment of fracture propensity in susceptible populations, conventional analyses do not adequately discriminate those at risk. We have developed an alternative technique based on a single plane bending stress analysis of the femoral neck, in a one legged stance. The work differs from previous efforts along these lines in that it uses data acquired by widely available, conventional bone mineral scanner systems. Moreover, the necessary structural properties of the femoral neck are computed directly from digital bone mineral image data, with an uncomplicated user interactive program. In addition to structural geometry, strength indices incorporating differences in loading and age changes in material strength, are also computed. Preliminary work indicates that structural geometry may be reliably obtained by the method and strength estimates for cadaver femora correlate better with experimentally measured strength than does conventional bone mineral density. This investigation will be designed to determine the intrinsic physical and biomechanical limitations of the method, and to compare its sensitivity and selectively to conventional bone mineral analysis, in both patients and cadaver specimens. Physical limitations will be examined with a computer model of the scanner system, incorporating system geometry, sampling considerations, source emission spectra and tissue attenuation properties. Secondly, a thorough investigation of patient positioning error on geometric measurements will be conducted with a realistic hip phantom. Thirdly, the validity of the single plane bending stress analysis will be evaluated by comparison with finite element analyses using hip image data. Results of these efforts will be used for refinement of the methodology for clinical implementation. Application to patient populations will begin with an examination of the contralateral hip of acute osteoporotic hip fracture subjects. In a larger scale effort, hip bone mineral data from several unrelated, on- going studies dealing with osteoporosis will be supplied for hip strength analysis. These studies include: subjects from the Baltimore Longitudinal Sample on Aging, subjects from two different studies of postmenopausal women under different treatment regimens, and para- and quadriplegic subjects studied serially post trauma, or with long standing paralysis.