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，骨筛查是不准确的，骨折风险模型相对粗糙。一种利用x射线光谱测量的新放射学技术可以在一个程序中进行几种不同的测试。收集光束通过两层或三层不同材料传输的完整光谱，并根据光谱数据计算每种材料的面密度。我们程序的目标是提高双能x射线吸收仪（DXA）体内和患者特异性骨密度测量的准确性，被称为“金标准”。两种多能量辐射组件的硬化导致体内骨密度（BMD）测量依赖于体型和体重变化，并对当代平面DXA设备的灵敏度和准确性产生固有的系统性限制。我们的初步结果表明，所提出的光谱骨密度测量方法简单、准确、无光束硬化、辐射剂量低，适合临床应用。本文提出了光谱成像（类dxa投影成像）的概念和三材料（骨、瘦软组织和脂肪组织）分解方法。结合我们之前提出的x射线散射骨密度测量方法，光谱骨诊断设备不仅可以提供传统DXA中改进的“面”骨密度（骨密度单位为g/cm2）测量，还可以提供类似qct的小梁骨体积骨密度（“真实”密度单位为g/cm3）测量。因此，x射线光谱方法可能对国家诊断、监测治疗过程以及预防骨质疏松症和其他代谢性骨病的努力产生重大影响。骨质疏松症是一种常见的、沉默的、复杂的骨骼疾病，对我们老龄化人口的健康构成了重大威胁。该病的特点是骨量低，导致骨脆性增强，骨折风险显著增加，通常通过骨密度仪诊断[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].