Multi-view, Photon Counting DXA Scanner for Quantitative Musculoskeletal Imaging

描述（由申请人提供）：骨质疏松症骨的易碎性主要是由于底层结构几何形状的改变。研究表明，使用双能x射线吸收仪（DXA）扫描可以测量人体骨骼的机械几何形状。然而，DXA扫描仪设计用于测量骨矿物质密度（BMD），而不是结构几何。用于BMD的二维图像质量相对较差，不适合测量三维骨骼的几何形状。在这个第一阶段的SBIR项目中，我们建议使用一个全尺寸的台式系统来测试多投影DXA扫描仪的性能，该扫描仪旨在测量任何身体区域的骨骼几何形状，并获得更高质量的图像数据。该扫描仪将采用多行计数探测器阵列的狭缝扫描配置，以产生比任何现有的DXA系统更高质量的材料分解和更高的空间分辨率。通过调整x射线通量、扫描时间和/或光谱滤波器，该扫描仪设计用于适应通过厚身体区域或肥胖患者的投影，并且信噪比损失很小。在这个项目中，系统设计将完成，以便在第二阶段可以建立一个人类能力的原型并对人类进行测试。c臂龙门设计用于扫描从新生儿到99百分位成人的整个身体，无论患者是平卧还是直立。它也将扫描任何子区域在任何轴向投影。系统设计采用灵活的检测器接口和扫描配置，以便可以测试来自多个供应商的计数检测器。

DESCRIPTION (provided by applicant): The fragility of osteoporotic bones is largely due to alterations in the underlying structural geometry. Research has demonstrated that it is possible to measure the mechanical geometry of human bones in vivo using dual energy x-ray absorptiometry (DXA) scans. However DXA scanners are designed to measure bone mineral density (BMD) and not structural geometry. The 2-dimensional relatively poor quality images adequate for BMD are not well suited to measuring geometry of 3-dimensional bones. In this Phase I SBIR project we propose to use a full-sized benchtop system to test the properties of a multiple-projection DXA scanner designed to measure bone geometry in any body region with higher quality image data. The scanner will employ a multi-row array of counting detectors in a slot-scanning configuration to produce higher quality material decompositions and higher spatial resolution than any existing DXA system. The scanner is designed to accommodate projections through thick body regions or obese patients with little loss of SNR by adjusting the x-ray flux, scan time and or the spectral filter. In this project the system design will be completed so that a human capable prototype can be built and tested on humans in Phase 2. The C-arm gantry design is to be configured for scanning of the entire body with sizes from neonate to 99th percentile adults with the patient either recumbent or erect. It will also scan anybody sub-region in any axial projection. The system design employs a flexible detector interface and scanning configuration so that counting detectors from several vendors may be tested. PUBLIC HEALTH RELEVANCE: Bone densitometry scanners are designed to measure bone density as way to determine if patients are susceptible to osteoporotic fractures but current scanners are accurate only 50% of the time. The principles used in bone densitometry scanners can be employed to measure the bone structure for a more direct evaluation of bone strength, but scanners need better image quality and the ability to view bones from multiple directions. The purpose of this proposal is to test the principles of an x-ray scanner that uses spectral information to provide multiple high-quality views of patient's bones so that strength can be estimated using engineering methods. If successful a scanner capable of scanning patients either erect or recumbent will be built in Phase 2 and tested on human volunteers.