Digital Tomosynthesis-Based Microstructural Measures to Predict Vertebral Fragili

描述（由申请人提供）：骨质疏松导致的骨折是一个重大问题。椎体骨折是最常见的；每两名女性中就有一人在其一生中至少会发生一次椎体骨折。骨折风险定量评估的金标准是骨密度（BMD）。然而，通过BMD预测骨折风险的成功率有限。已知松质骨的其他微观结构特性有助于椎体骨质量的定量评估和骨强度的预测。然而，这些在体内很难在人体脊柱中测量。数字断层合成（DTS）是一种可以对物体聚焦平面进行成像的技术。由于物体的其他平面造成的图像模糊，使得使用x射线胶片进行定量分析非常困难，而DTS在很大程度上减少了这种模糊。在单次DTS扫描期间连续采集图像允许收集一系列图像，每个图像聚焦在物体的不同平面上。这提供了从物体的物理切片中获得的一系列x射线胶片的数字等效物。此外，DTS具有良好的平面内分辨率，速度快，相对便宜，并且使患者暴露于比CT扫描更低的辐射剂量。松质骨的微观结构/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相关，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成像的椎体骨脆性和骨折风险的改进标记物。在此期间，我们提出了一项体外研究，以检验DTS用于量化椎体骨微观结构和预测椎体骨衰竭特性的可行性。提出的具体目标是：1)使用人类尸体椎骨，确定DTS分析感兴趣区域的大小和平面，最大限度地提高DTS和微计算机断层扫描之间的相关性(？CT)参数，用？CT。2)利用人的尸体椎骨，？CT， DEXA， HRCT， DTS和力学测试，以确定基于DTS的微观结构变异性预测椎体强度和脆性的程度。3)利用人的尸体椎骨，？CT、DEXA、HRCT、DTS和力学测试确定了基于DTS的微观结构变异性预测椎体蠕变的程度。

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.