Spectroscopic X-ray Bone Densitometry

描述（由申请人提供）：骨质疏松症是美国老龄化人口面临的严重公共卫生问题。直到最近，骨骼筛查还是不准确的，骨折风险模型也相对粗糙。一种新的放射学技术使用X射线光谱测量，可以在一个过程中执行几个不同的测试。收集透过两层或三层不同材料的光束的完整光谱，并根据每种材料的光谱数据计算面密度。我们的程序的目标是提高双能X线吸收测定法（DXA）的体内和患者特异性BMD测量的准确性，被称为“金标准”。两种多能辐射成分的硬化导致体内骨矿物质密度（BMD）测量对身体尺寸和体重变化的依赖性，并对当代平面DXA设备的灵敏度和准确性产生固有的系统限制。我们的初步结果表明，所提出的光谱BMD测量方法是简单，准确，射束硬化免费，涉及低辐射剂量，是非常适合于临床使用。光谱成像的概念（类DXA投影成像）和三种材料（骨，瘦软组织和脂肪组织）的分解方法包括在这个建议。结合我们先前提出的X射线散射骨密度测定方法，光谱骨诊断设备不仅可以提供如传统DXA中的“面积”骨矿物质密度（BMD，g/cm 2）的改进测量，而且可以提供骨小梁的类似QCT的体积BMD（“真实”密度，g/cm 3）。因此，X射线光谱法可能对国家诊断、监测治疗过程以及预防骨质疏松症和其他代谢性骨疾病的努力产生重大影响。骨质疏松症是一种常见的，无声的，复杂的骨骼疾病状态，对我们的老龄化人口构成了重大的健康威胁。该疾病的特征是骨量低，导致骨脆性增强和骨折风险显著增加，通常通过骨密度仪进行诊断[1，2]。

DESCRIPTION (provided by applicant): Osteoporosis is a serious public health problem faced by an aging US population. Until recently, bone screening was inaccurate and models of fracture risk were relatively crude. A new radiological technique using measurements of the X-ray spectrum can perform several different tests in a single procedure. The complete spectrum of a beam transmitted through two or three different layers of material is collected and areal densities are calculated from the spectral data for each material. The goal of our procedure is to improve the accuracy of in-vivo and patient-specific BMD measurement of Dual-Energy X-ray Absorptiometry (DXA), referred as the "gold standard". Hardening of the two poly-energetic radiation components results in a dependence of in-vivo bone mineral density (BMD) measurements on body size and on weight change and yields an inherent systematic limitation to the sensitivity and accuracy of contemporary planar DXA devices. Our preliminary results suggest that the proposed method of spectral BMD measurement is simple, accurate, beam hardening free, involving low radiation dosage, and is well suited for clinical use. The concept of spectroscopic imaging (DXA-like projection imaging) and a three-material (bone, lean soft tissue, and adipose tissue) decomposition method are included in this proposal. In conjunction with our previously proposed X-ray scattering bone densitometry method, a spectroscopic bone diagnostic device can offer not only an improved measurement of "areal" bone mineral density (BMD in g/cm2), as in conventional DXA but also a QCT-like volumetric BMD (a "true" density in g/cm3) for trabecular bone. Thus, the X-ray spectroscopic method may have a significant impact on national efforts to diagnose, monitor the course of treatment, and to prevent osteoporosis and other metabolic bone diseases. Osteoporosis is a common, silent, and complex disease state of bone that poses a major health threat to our aging population. The disease is characterized by low bone mass, leading to enhanced bone fragility and a significant increase in the risk of fractures, which is typically diagnosed by bone densitometer [1,2].