In-vivo MR Tractography and FEM Study of Human Lower Leg

人体小腿的体内 MR 纤维束成像和 FEM 研究

• 批准号: 7026189
• 负责人: Shantanu Sinha
• 金额: $ 29.15万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-15 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7026189
• 关键词: clinical research; human; leg; model; muscle

DESCRIPTION (provided by applicant): Current models of the musculo-skeletal system fail to accurately predict the relationship between muscle fiber shortening and the relative excursion of the tendino-skeletal interfaces. A simple example of this would be that the tendino-calcaneal interface at the ankle moves approximately 30 mm for a 15 mm soleus muscle fiber shortening. We propose multiple mechanical gain systems to amplify the muscle fiber excursion and the basic design of this proposal is to evaluate these gain systems and determine if they are sufficient to explain the discrepancy between muscle fiber length changes and movement of the ankle. A secondary goal is to understand the underlying mechanics, particularly as it relates to the distortion of muscle tissue during a contraction. The hypotheses to be tested include (1) The proximo-distal displacement of the fiber-aponeurosis interface during an isometric contraction will be due in part to an increase in angle of the interface as well as due to a shortening of the distance between the aponeuroses of insertion and origin, and (2) The proximo-distal displacement of the most distal soleus fiber-aponeurosis of insertion will be less than the linear displacement of the Achilles' tendon insertion point on the calcaneus due to a sling factor that is intrinsic to the musculotendinous-skeletal anatomy. Advanced MR imaging techniques of fiber tracking with Diffusion Tensor Tractography at 3 Tesla, Phase Contrast Imaging, and MRI-compatible dynamometry as well as Finite Element Modeling will be used in combination. This is particularly apt for the PA which asks that a "multidisciplinary research" with an "integration of principles from a diversity of technical and biomedical field" be used to "provide new understanding" and "effectively address a biomedical problem". We will experimentally investigate several design features of the Triceps Surae Complex that could account for apparent paradoxes in current descriptions of muscle performance and generate a model consistent with our experimental observations. Our goal is better prediction of intrinsic muscle properties and joint performance. Essential variables that we will measure to test these hypotheses include muscle volume, muscle surface area, fiber orientation, aponeurosis separation (muscle thickness), aponeurosis dimension and strain properties of aponeurosis. In 3Dal space, these variables will be quantified at systematically varying ankle joint positions and muscle activation levels. From a past grant from NASA/NSBRI, we have had considerable success in developing most of these relatively difficult techniques, (as per publications in Appendix). The developed model will help to gain better insight into the design features of muscle-tendon complex, a better understanding of chronic muscle adaptations such as disuse atrophy and better prediction of outcomes of surgical treatments such as aponeurotomy, tenectomy and tenotomy.

描述（由申请人提供）：肌肉 - 骨骼系统的当前模型无法准确预测肌肉纤维缩短与tendino-Skelet界面的相对游览之间的关系。一个简单的例子是，脚踝处的Tendino-Calcaneal界面可移动约30毫米，以进行15毫米的比目鱼肌纤维缩短。我们提出了多种机械增益系统来扩大肌肉纤维的偏移，该建议的基本设计是评估这些增益系统，并确定它们是否足以解释肌肉纤维长度变化和踝关节运动之间的差异。第二个目标是了解潜在的力学，尤其是在收缩过程中与肌肉组织的失真有关。要测试的假设包括（1）等距收缩期间纤维 - 尿尿症界面的近端位移将部分归因于界面角度的增加，以及由于插入和起源的插入式距离之间的距离缩短了距离的距离较少，并且（2）距离距离较少的距离距离距离距离较少。阿喀琉斯肌腱插入点的线性位移是由于吊带因子固有的，这是肌肉骨骼骨骼解剖结构的固有的。在3个TESLA，相比成像和与MRI兼容的动力学以及有限元建模的纤维跟踪的先进MR成像技术将用于组合使用。这对于PA尤其倾向于要求“多学科研究”与“来自各种技术和生物医学领域的原理整合”，以“提供新的理解”并“有效解决生物医学问题”。我们将在实验中研究三头肌辅助复合物的几种设计特征，这些设计特征可以解释当前对肌肉性能的描述，并生成与我们的实验观察一致的模型。我们的目标是更好地预测内在的肌肉特性和关节性能。我们将测量这些假设的基本变量包括肌肉体积，肌肉表面积，纤维取向，肌肌分离（肌肉厚度），阿替尿的肌肌张力和应变特性。在3DAL空间中，这些变量将在系统变化的踝关节位置和肌肉激活水平上进行量化。从NASA/NSBRI的过去拨款中，我们在开发大多数这些相对困难的技术方面取得了巨大的成功（根据附录中的出版物）。开发的模型将有助于更好地洞悉肌肉刺激复合体的设计特征，对慢性肌肉适应性（例如失去萎缩）以及对手术治疗的结果（例如腹膜内切开术，骨膜切除术和替型术）的预测有了更好的了解。