Advanced, multiple-projection, dual-energy x-ray absorptiometry system: Precision bone loss measurements on earth and in space
Advanced, multiple-projection, dual-energy x-ray absorptiometry system: Precision bone loss measurements on earth and in space
复制标题
先进的多重投影双能 X 射线吸收测量系统：在地球和太空中进行精确的骨质流失测量
DOI：
--
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
T. Beck
中科院分区：
文献类型：
--
作者：
H. Charles;H. Feldmesser;T. C. Magee;T. Beck
JOHNS HOPKINS APL 技术文摘，第 28 卷，第 3 期 (2010) 212 年龄相关性骨质疏松症和微重力引起的骨质流失的机制是进行精确骨质流失和骨结构测量的能力。目前评估骨质流失或骨矿物质密度 (BMD) 的测量方法受到严重限制。它们对患者位置敏感，并且仅生成骨骼的 2D 表示，从而丢失有关 3D 密度、骨骼几何形状和骨骼结构的重要信息。当今的方法无法区分致密骨和松质骨（多孔），导致无法构建执行应力载荷和骨折模拟分析所需的骨骼工程模型。我们的方法使用双能 X 射线的三个投影，其中两个投影关于位于中心的第三个投影对称。如果两个外部投影正交 (90°)，则骨机械特性（例如惯性矩）的推导很简单。在人类中，由于其他骨骼和骨骼方向的重叠，很难获得 90°。先进的多投影双能 X 射线吸收测定法 (AMPDXA) 方法克服了这个问题，只需 30° 的角展度即可进行投影（见图 1）。 AMPDXA 项目是 APL 和 JHU 医学院团队的共同努力。这项工作持续了 9 年（1998 年至 2007 年），主要由国家空间生物医学研究所 (NSBRI) 资助。该项目取得了显着的技术成果，包括：
JOHNS HOPKINS APL TECHNICAL DIGEST, VOLUME 28, NUMBER 3 (2010) 212 mechanisms of both age-related osteoporosis and microgravity-induced bone loss is the ability to make precision bone loss and bone structural measurements. Current measurement methods for assessing bone loss or bone mineral density (BMD) are severely limited. They are sensitive to patient position, and they produce only a 2-D representation of the bone, thus losing important information about the 3-D density, bone geometry, and bone structure. Today’s methods cannot distinguish between compact and cancellous (porous) bone, resulting in the inability to construct an engineering model of the bone necessary to perform stress loading and fracture-simulation analysis. Our methods use three projections of dual-energy x-rays, two of which are located symmetrically about the centrally located third projection. Derivation of a bone mechanical property such as the moment of inertia is straightforward if two outer projections are orthogonal (90°). In humans, it is difficult to obtain 90° because of the overlap of other bones and bone orientation. The Advanced, Multiple-Projection, Dual-Energy X-Ray Absorptiometry (AMPDXA) approach overcomes this problem, requiring projections over only a 30° angular spread (see Fig. 1). The AMPDXA Project was a joint effort by a team from APL and the JHU School of Medicine. The effort, which lasted for 9 years (1998–2007), was funded primarily by the National Space Biomedical Research Institute (NSBRI). This project produced significant technical results, including the following: