Non-Invasive Evaluation of In Vivo Intervertebral Disc Mechanical Function

项目摘要 椎间盘具有力学功能，随着椎间盘结构和功能的退变和老化 会引起腰痛。影像学通常用于通过椎间盘评估椎间盘结构和健康状况 分级方案，但不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MRI成像中的功能评估。目前迫切需要在体内测量椎间盘的力学功能 并通过诊断和治疗脊柱病理的功能能力来评估椎间盘健康。 已经在尸体模型中评估了机械功能，但是体内和 尸体状态纯粹是推测性的，因为缺乏共同的参考状态和未知的差异 他们之间体内条件的边界和载荷条件尚未量化， 因此不能在尸体试验或有限元模型（FEM）中复制。本提案的目的 是量化椎间盘在体内的机械功能，建立一个基于功能的椎间盘分级方案， 并创建体内人类椎间盘FEM。我将测量体内椎间盘应变，使用动物模型建立一个 体内和尸体条件之间的平移矩阵，并使用FEM预测椎间盘的内部 体内的机械状态。 目的1：量化具有退化和老化的人类在体椎间盘的机械功能 目前的椎间盘分级方案是基于结构的，不能区分正常的老化和变性， 椎间盘病理学;我将使用多位置MRI评估体内椎间盘功能，并建立统计模型， 一种新的多因子光盘分级方案。 目的2：在猪模型中建立体内和尸体状态之间的转换矩阵 将使用动物模型进行体内和尸体条件之间的配对MRI定量。 离体力学测试和配对体内FEM将能够进一步比较条件。这些 量化将允许我建立体内和尸体状态之间的转换矩阵。 目的3：创建和重现体内人类椎间盘FEM 将对来自目标1的MRI载荷数据、来自目标2的转换矩阵和先前确认的椎间盘模型进行分析。 用于创建和验证体内人体椎间盘FEM，以评价体内椎间盘的内部力学。 这项研究将产生一个功能为基础的光盘分级计划，以取代以前的结构为基础的计划。它将 建立体内和尸体状态之间的转换矩阵，这是解释的必要步骤 体内研究数据以及体外力学测试和FEM的适当设置。的 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，临床工具的诊断和评估的治疗选择腰痛。

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.