Non-Invasive Determination of Bone Quality Markers by Monte Carlo Modeling and Optical Spectroscopy

摘要： 骨质疏松症等骨脆性疾病需要骨质量监测，通常由双X- 射线吸收法(DXA)评估骨密度(BMD)。骨健康指数(BHI)和 掌骨指数(MCI)是其他测量骨质量的指标，基于放射学几何评估 从平面手X光中获得的掌骨。这些方法都使用电离辐射，这是 在一些人口中受到关注，在资源匮乏的社区可能不容易获得。然而，X- 来自掌骨的射线数据已被证明是椎骨骨折风险的重要预测因子。 和髋关节，并与DXA测定的BMD相关。在这里，我们建议开发一种替代方法 对于掌骨健康的评估，近红外(NIR)光谱与光纤相结合 探测器。这是一种基于低能量非电离辐射的非侵入性模式，也可以产生 与被评估的材料或组织的质量有关的分子信息。在目前的提案中， 骨质量的近红外光谱分析将以多步骤的方法进行优化。特定的光学性质 将获得掌骨和上覆组织的比例，然后将其用作蒙特卡罗建模的输入 光子穿透皮肤和骨骼的能力。然后，这些数据将用于通知和优化设计 近红外光纤探头，这样收集的光谱数据优先来自骨骼，而不是 覆盖在上面的组织。推进近红外光谱分析用于骨质量的临床评估需要谨慎 开发专门用于光谱分析的专用探头和技术 掌骨的测量。这种方式的发展最终可能导致 用于社区骨骼健康筛查的直截了当、经济高效的方法。

Summary: Diseases of bone fragility such as osteoporosis require bone quality monitoring, typically done by dual X- ray absorptiometry (DXA) assessment of bone mineral density (BMD). Bone health index (BHI) and metacarpal index (MCI) are other measures of bone quality based on radiographic geometric assessment of the metacarpal bones obtained from a planar hand X-ray. These approaches all use ionizing radiation, which is of concern in some populations, and may not be easily accessed in low-resource communities. Nevertheless, X- ray data from the metacarpal bones have been shown to be a significant predictor of fracture risk at the vertebrae and hip, and to correlate with DXA-determined BMD. Here, we propose development of an alternative approach for metacarpal assessment for bone health, near infrared (NIR) spectroscopy combined with a fiber optic probe. This is a non-invasive modality based on low energy non-ionizing radiation that can also yield molecular information related to the quality of material or tissue being evaluated. In the current proposal, NIR spectroscopic analysis of bone quality will be optimized in a multi-step approach. Specific optical properties of metacarpal bones and the overlying tissues will be obtained, and then used as input into Monte Carlo modeling of photon penetration through skin and bone. These data will then be used to inform and optimize the design of NIR fiber optic probes such that the spectral data collected preferentially comes from bone, as opposed to overlying tissues. Advancing NIR spectroscopy for clinical assessment of bone quality will require the careful development of application-specific probes and techniques for spectral analysis uniquely tailored for measurement of the metacarpal bone. Development of this modality could eventually lead to the development of straight-forward, cost effective approaches for community screening of bone health.