Digital Tomosynthesis-Based Microstructural Measures to Predict Vertebral Fragili

描述(申请人提供)：骨质疏松症导致的骨折是一个严重的问题。脊椎骨折是最常见的骨折之一；预计每两名女性中就有一人在一生中至少有一次脊椎骨折。定量评估骨折风险的金标准是骨密度(BMD)。然而，根据骨密度预测骨折风险的成果有限。已知松质骨的其他微结构特性有助于定量评估椎骨质量和预测骨强度。然而，这些都很难在活体人体脊椎中测量。数字断层合成(DTS)是一种允许对物体中的聚焦平面进行成像的技术。DTS在很大程度上减少了由物体的其他平面引起的图像模糊，这将使使用X射线胶片进行定量分析变得非常困难。在单个DTS扫描期间连续采集图像允许收集一系列图像，其中每个图像聚焦在对象的不同平面上。这提供了从物体的物理切片获得的一系列X射线胶片的数字等价物。此外，DTS具有良好的面内分辨率，速度快，相对便宜，并且比CT扫描暴露在较低的辐射剂量下。松质骨的微结构/纹理参数已被发现具有临床意义，并与椎骨的重要力学特性有关，可以在DTS图像上进行分析。然而，DTS在骨质量定量分析中的价值尚未得到检验。因此，我们的总体目标是开发基于DTS成像的改进的椎骨脆性和骨折风险标记物。在此期间，我们提出了一项体外研究，以检验DTS用于量化椎骨微结构和使用人类身体椎骨预测椎骨破坏特性的可行性。建议时期的具体目标是：1)使用人的身体脊椎，确定DTS分析的感兴趣区域的大小和平面，使DTS与显微计算机断层扫描(？CT)参数之间的相关性最大化，并用？CT校准DTS。2)利用人体身体椎骨、CT、DEXA、HRCT、DTS和力学测试，确定基于DTS的显微结构变异性预测椎体强度和脆性的程度。3)利用人体身体椎骨、CT、DEXA、HRCT、DTS和力学测试，确定基于DTS的显微结构变异预测脊椎蠕变的程度。 公共卫生相关性：该项目旨在确定一种临床可用的成像系统的新应用，即数字断层合成，是否可以用于测量脊椎骨骼的微结构特性，并预测脊椎的强度、脆性和变形。这些结果将被用于定义参数，这些参数可以更有效地估计脊椎骨折风险和恢复骨骼结构的策略。从这项研究中获得的知识可能会极大地改变我们预测骨折风险和治疗骨质疏松症的临床方法，骨质疏松症是一种对老年人口有很大影响的疾病。

DESCRIPTION (provided by applicant): Bone fractures attributable to osteoporosis are a significant problem. Vertebral fractures are among the most common; everyone in two women is expected to have at least one vertebral fracture in their lifetime. The gold-standard for quantitative assessment of fracture risk is bone mineral density (BMD). However, prediction of fracture risk from BMD has had limited success. Additional microstructural properties of cancellous bone are known to contribute to the quantitative assessment of vertebral bone quality and prediction of bone strength. However, these are difficult to measure in human spine in vivo. Digital tomosynthesis (DTS) is a technique that allows for imaging of focused planes in objects. The blurring in the image that is caused by other planes of the object which would make quantitative analysis using an x-ray film very difficult is reduced to a great extent in DTS. The successive acquisition of images during a single DTS scan allows for collection of a series of images each of which is focused on a different plane of the object. This provides a digital equivalent of a series of x-ray films that would be obtained from physical slices of the object. Furthermore, DTS has a good in-plane resolution, fast, relatively cheap and exposes the patient to a lower radiation dose than a CT scan. The microstructure/texture parameters of cancellous bone that have been found to have clinical significance and related to important mechanical properties of vertebrae are amenable to analyses that can be performed on DTS images. However, DTS has not been examined for its value in quantitative analysis of bone quality. Therefore, our overall goal is to develop improved markers of vertebral bone fragility and fracture risk based on DTS imaging. In this period, we propose an in vitro study to examine the feasibility of DTS for quantification of vertebral bone microstructure and for predicting vertebral bone failure properties using human cadaveric vertebrae. The specific goals of the proposed period are: 1) Using human cadaver vertebrae, determine the size and plane of regions of interest for DTS analysis that maximize correlation between DTS and microcomputed tomography (?CT) parameters, and calibrate DTS with ?CT. 2) Using human cadaver vertebrae, ?CT, DEXA, HRCT, DTS and mechanical testing, to determine the extent to which DTS-based microstructural variability predicts vertebral strength and brittleness. 3) Using human cadaver vertebrae, ?CT, DEXA, HRCT, DTS and mechanical testing, determine the extent to which DTS-based microstructural variability predicts vertebral creep. PUBLIC HEALTH RELEVANCE: This project is designed to determine whether a new application of a clinically available imaging system, namely digital tomosynthesis, can be used to measure vertebral bone microstructural properties and predict vertebral strength, brittleness and deformation. The results will be used to define parameters that can be more effective in estimating vertebral fracture risk and strategies to restore bone structure. The knowledge gained form this research may substantially change our clinical approach for predicting risk of fracture and treating osteoporosis, a disease with a large impact on the elderly population.