IN-VIVO VERTEBRAL BONE ARCHITECTURE IN OSTEOPOROSIS

我们最近开发了x射线计算机断层扫描方法。 准确测量区域骨密度(RBMD) 在单个椎骨的小体积(0.004cc)内产生 详细的(n=655,360)椎体的三维标测 人类受试者的RBMD。与之前计算的结果相比 断层扫描方法，分析人体内的骨密度 单量大，区域法生产的完整 一种骨材料的空间分布描述 脊椎骨。我们的初步结果表明，脊椎 松质骨以不同的、不均匀的图案分布 在椎体内。 这项拟议的研究的目标是在活体内表征 基于测量的RBMD和BMD的椎骨结构 评估骨骼结构变化的假设 与代谢性骨骼疾病相关的疾病在 脊椎骨折的发病机制。具体来说，我们希望 提高我们描述测量的RBMD数据的能力， 无症状患者椎体径向密度特征的评价 志愿者和患有轻度骨质疏松疾病的受试者， 确定椎体骨丢失是否发生在局部 变异，并测量RBMD和 活体试件的力学性能。 总体而言，拟议的研究涉及以下衡量标准 800个新的活体椎体的椎体RBMD(数据已经 在200)和336个体外测量中获得 标本。每个椎骨的骨骼结构将是 详细描述了由31个参数计算得出的三个 RBMD的维度映射。

We have recently developed x-ray computed tomography methods to accurately measure the regional bone mineral density (rBMD) within small volumes (.004cc) of individual vertebra and produce detailed (n = 655,360), three dimensional mappings of vertebral rBMD for human submects. Compared to previous computed tomography methods, which assay the bone mineral density within single large volumes, the regional method produces a complete description of the spatial distribution of bone material in a vertebra. Our preliminary results indicate that vertebral cancellous bone is distributed with varied, non-uniform patterns within the vertebral body. The objective of the proposed research is to characterize in-vivo vertebral bone architecture based on measured rBMD and evaluate the hypothesis that changes in bone architecture associated with metabolic bone disease are of importance in the pathogenesis of vertebral fractures. Specifically we wish to improve our ability to characterize measured rBMD data, evaluate the vertebral rBMD characteristics of asymptomatic volunteers and subjects with minimal osteoporotic disease, establish whether vertebral bone loss occurs with regional variations, and measure the relationship between rBMD and the mechanical properties of in-vivo specimens. Overall, the proposed research involves measurements of vertebral rBMD on 800 new in-vivo vertebrae (data has already been acquired on 200) and 336 measurements on in-vitro specimens. The bone architecture of each vertebra will be described by 31 parameters computed from the detailed, three dimensional mapping of rBMD.