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 准确测量局部骨密度（rBMD） 在单个椎骨的小体积（.004cc）内， 详细（n = 655，360），椎体三维标测 人受试者的rBMD。 与此前计算的 断层扫描方法，其测定骨矿物质密度， 单卷量大，区域方法产生完整的 描述骨材料的空间分布， 脊椎骨 我们的初步结果表明， 松质骨分布多样，不均匀 在椎体内。 拟议研究的目的是表征体内 基于测量的rBMD的椎骨骨结构， 评估骨骼结构变化的假设， 与代谢性骨病相关的重要性， 脊椎骨折的发病机制。 具体来说，我们希望 提高我们表征测量rBMD数据的能力， 评估无症状患者的椎体rBMD特征， 志愿者和受试者患有轻微的阿尔茨海默病， 确定脊椎骨丢失是否发生在区域性 变化，并测量rBMD和 体内样本的机械性能。 总的来说，拟议的研究涉及测量 800个新体内椎骨的椎骨rBMD（数据已经 在200次测量和336次体外测量中获得 标本 每个椎骨的骨结构将是 由31个参数描述，这些参数是从详细的、三个 rBMD三维定位。

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.