MYOCARDIAL FUNCT USING SPATIOTEMPORAL FINITE ELEMENT MESH MODEL & VELOCITY DATA

使用时空有限元网格模型的心肌功能

• 批准号: 6309993
• 负责人: YUDONG ZHU
• 金额: $ 1.55万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2000-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6309993
• 关键词: bioengineering /biomedical engineering; bioimaging /biomedical imaging; biomedical resource; cardiovascular system; magnetic resonance imaging; radiology; technology /technique

Introduction: Phase contrast velocity data can be used to compute motion and deformation of a myocardial region. We present a method that uses a global spatiotemporal finite element model to improve the reproducibility of the computation while retain high accuracy, as compared to a local computation method. Methods and Results: We consider a partition of a large myocardial region with non-overlappingtime-varying basic mesh elements. Nodal points of the mesh covering the region are selected at a reference state. These material points and corresponding spatiotemporal trajectories define the time-varying domain of each mesh element. Within each element, we model the kinematics using finite element shape functions. In implementation, with a reference state mesh configuration defined by the user, and initial estimates of the subsequent mesh configurations obtained by independent tracking of node points, we iteratively refine the mesh configuration estimates by fitting the velocity data to the spatiotemporal finite element model. Reproducibility of the computed quantities can be analyzed after after each computation. In a validation study, we synthesized a 2-D nonuniform deformation data set with an apprent SNR of 45. We computed the motion and deformation quantities from analyzing a single triangular mesh element in case 1 and analyzing an extended mesh configuration that consisted of the same element plus three additional neighboring elements of compariable size in case 2. Repeating the data synthesis and analysis 1000 times for mean and standard deviation measurements showed that the averages of the estimated quantities were in excellent agreement with the true values in both cases. Comparing the results for the same mesh element in the two cases indicated that the extended mesh modeling resulted in lower standard deviation but comparably high accuracy. Summary and Conclusion: Analyzing a single element domain with the present method and the previous local method have about the same reproducibility. With the present method, extending the finite element mesh by adding more triangular elements achieves increasing reproducibility. At the same time, due to the piecewise parameterization, high estimation accuracy, comparable to that of the local method, can still be obtained.

简介：相衬速度数据可用于计算 心肌区域的运动和变形。 我们提出一个方法 使用全局时空有限元模型来改进 计算的可重复性，同时保持高精度，如 与本地计算方法相比。 方法和结果：我们 考虑大心肌区域的划分 非重叠时变基本网格元素。 的节点 覆盖该区域的网格是在参考状态下选择的。 这些 物质点和相应的时空轨迹定义 每个网格元素的时变域。 在每个元素中，我们 使用有限元形状函数对运动学进行建模。 在 实现，具有由以下定义的参考状态网格配置 用户以及后续网格配置的初始估计 通过独立跟踪节点点获得，我们迭代细化 通过将速度数据拟合到网格配置来估计 时空有限元模型。 计算结果的再现性 每次计算后都可以对数量进行分析。 在一个 验证研究，我们合成了一个二维非均匀变形数据集 明显的 SNR 为 45。我们计算了运动和变形 分析案例 1 中单个三角形网格单元的数量 并分析由以下组成的扩展网格配置 相同的元素加上三个附加的可比较的相邻元素 案例2中的大小。重复数据合成和分析1000次 平均值和标准差测量表明平均值 的估计数量与真实数量非常吻合 两种情况下的值。 比较相同网格元素的结果 在这两种情况下表明扩展网格建模导致 标准偏差较低，但准确度较高。 总结和 结论：用本方法分析单元素域 和之前的本地方法具有大致相同的再现性。 使用本方法，通过添加来扩展有限元网格 更多的三角形元素可以提高再现性。 在 同时，由于分段参数化，估计值较高 与本地方法相比，准确率仍然可以 获得。