PDF(Pubmed)
Abstract：
Objective.Virtual imaging trials enable efficient assessment and optimization of medical image devices and techniques via simulation rather than physical studies. These studies require realistic, detailed ground-truth models or phantoms of the relevant anatomy or physiology. Anatomical structures within computational phantoms are typically based on medical imaging data; however, for small and intricate structures (e.g. trabecular bone), it is not reasonable to use existing clinical data as the spatial resolution of the scans is insufficient. In this study, we develop a mathematical method to generate arbitrary-resolution bone structures within virtual patient models (XCAT phantoms) to model the appearance of CT-imaged trabecular bone.Approach. Given surface definitions of a bone, an algorithm was implemented to generate stochastic bicontinuous microstructures to form a network to define the trabecular bone structure with geometric and topological properties indicative of the bone. For an example adult male XCAT phantom (50th percentile in height and weight), the method was used to generate the trabecular structure of 46 chest bones. The produced models were validated in comparison with published properties of bones. The utility of the method was demonstrated with pilot CT and photon-counting CT simulations performed using the accurate DukeSim CT simulator on the XCAT phantom containing the detailed bone models.Main results. The method successfully generated the inner trabecular structure for the different bones of the chest, having quantiative measures similar to published values. The pilot simulations showed the ability of photon-counting CT to better resolve the trabecular detail emphasizing the necessity for high-resolution bone models.Significance.As demonstrated, the developed tools have great potential to provide ground truth simulations to access the ability of existing and emerging CT imaging technology to provide quantitative information about bone structures.
摘要：
虚拟成像试验(VIT)能够通过模拟而不是物理研究来实现对医学图像设备和技术的有效评估和优化。这些研究需要精确的成像系统仿真模型,相关解剖学或生理学的详细的地面实况模型或幻影。计算体模内的解剖结构通常基于医学成像数据，通常是CT或MRI。然而,对于小而复杂的结构(例如，骨小梁)，使用现有的临床数据来通知计算模型是不合理的，因为扫描的空间分辨率不足。该分辨率导致呈现为图像特征或纹理而不是形态的精细小梁结构。以前,我们开发了一种基于成像数据的合成纹理的CT成像小梁骨外观建模方法。在这项研究中,我们开发了一种数学方法来在虚拟患者模型（XCAT幻影）中生成任意分辨率的骨骼结构。该方法用于生成46个胸骨的小梁和皮质结构，水密,具有骨骼和红骨髓区域的2-流形（多边形网格）。所产生的模型与已发表的骨骼特性进行了比较验证。使用精确的DukeSimCT模拟器在包含详细骨骼模型的XCAT计算体模上进行的飞行员CT和光子计数CT模拟证明了该方法的实用性。结果表明，所开发的工具具有提供地面实况模拟以访问CT成像技术提供有关骨骼结构的定量信息的能力的巨大潜力。
