Non-Invasive Evaluation of In Vivo Intervertebral Disc Mechanical Function

项目摘要 椎间盘具有机械功能，有退变和老化的椎间盘结构和功能 会引起腰背痛。成像通常被用来通过椎间盘评估椎间盘结构和健康状况 分级方案，但未能识别临床相关的椎间盘变化。这可能是由于缺乏机械。 静态磁共振成像中的功能评估。迫切需要在活体内测量椎间盘的机械功能 并通过诊断和治疗脊柱病理的功能能力来评估椎间盘的健康状况。 已经在身体模型中评估了机械功能，但体内和 身体状态纯粹是推测，因为缺乏共同的参考状态和未知的差异 在他们之间。活体条件的边界和加载条件尚未量化， 因此，不能在身体测试或有限元模型(FEM)中复制。这项提议的目的是 在活体内量化椎间盘的机械功能，建立以功能为基础的椎间盘分级方案， 并创建了活体人体圆盘有限元模型。我将在体内测量椎间盘应变，使用动物模型建立 体内和身体状态之间的转换矩阵，并使用有限元来预测椎间盘的内部 体内的机械状态。 目的1：在退变和老化的活体椎间盘中量化人的机械功能 目前的视盘分级方案是基于结构的，不能区分正常老化和退变 腰椎间盘病理：我将使用多位置MRI来评估活体腰椎间盘功能并建立统计模型 一种新的多因素圆盘分级方案。 目的2：建立猪活体和身体状态之间的翻译矩阵 一个动物模型将被用来在活体和身体条件之间进行成对的磁共振定量。 体外力学测试和在体有限元配对将使条件之间的进一步比较成为可能。这些 量化将使我能够建立活体和身体状态之间的转换矩阵。 目标3：在活体人体盘有限元中创建和验证 从AIM 1加载数据的MRI、从AIM 2加载的变换矩阵和先前验证的椎间盘模型将是 用于创建和验证用于评估体内盘的内部力学的活体人体盘内有限元。 这项研究将产生一种基于功能的光盘分级方案，以取代以往基于结构的方案。会的 建立活体和身体状态之间的转换矩阵，这是解释的关键步骤 在活体环境下的研究数据，并为体外机械测试和有限元建立适当的设置。这个 这项工作的主要影响将是研究椎间盘病理所需的方法和技术 从长远来看，这是诊断和评估腰背痛治疗方案的临床工具。

Project Summary The intervertebral disc has a mechanical function, with degeneration and aging the disc structure and function are altered which can cause low back pain. Imaging is often used to evaluate disc structure and health via disc grading schemes but fail to identify clinically relevant disc changes. This may be due to the lack of mechanical function assessment in static MRI imaging. There is a critical need to measure disc mechanical function in vivo and evaluate disc health by functional capacity to diagnose and treat spine pathology. Mechanical function has been evaluated in cadaver models, but the relationship between the in vivo and cadaveric states is purely speculative, due to the lack of common reference state and unknown differences between them. The boundary and loading conditions of the in vivo condition have not been quantified and therefore cannot be replicated in cadaveric tests or finite element models (FEM). The objective of this proposal is to quantify the disc’s mechanical function in vivo, establish a function-based disc grading scheme, and create an in vivo human disc FEM. I will measure in vivo disc strain, use an animal model to establish a translational matrix between in vivo and cadaveric conditions, and use a FEM to predict the disc’s internal mechanical state in vivo. Aim 1: Quantify Mechanical Function of Human In Vivo Disc with Degeneration and Aging Current disc grading schemes are structure-based and cannot distinguish normal aging and degeneration from disc pathology; I will use multi-positional MRI to assess in vivo disc function and a statistical model to establish a novel multi-factorial disc grading scheme. Aim 2: Establish a Translational Matrix Between In Vivo and Cadaver States in a Porcine Model An animal model will be used to conduct paired MRI quantifications between in vivo and cadaver conditions. Ex vivo mechanical testing and paired in vivo FEM will enable further comparison between conditions. These quantifications will allow me to establish a translation matrix between the in vivo and cadaveric states. Aim 3: Create and Validate In Vivo Human Disc FEM MRI loading data from Aim 1, transformation matrix from Aim 2 and a previously validated disc model will be used to create and validate an in vivo human disc FEM for evaluating the internal mechanics of the in vivo disc. This study will yield a function-based disc grading scheme to replace prior structure-based schemes. It will establish a transformation matrix between in vivo and cadaveric states, an essential step for interpreting research data in the in vivo context and for appropriate setup for ex vivo mechanical testing and FEM. The main impact of this work will be the methods and techniques needed for research to investigate disc pathology and in the long term, clinical tools for the diagnosis and assessment of treatment options for low back pain.