提高乳腺电阻抗成像空间分辨率的研究
发布时间：2018-11-18 21:54
【摘要】：电阻抗成像技术是一种新型的生物医学成像技术，它是通过在目标区域注入电流，然后测量其表面电压，得到目标区域内部电导率的分布。基于恶性肿瘤组织的电导率与健康乳腺组织或良性肿瘤组织存在着显著差异，本文采用电阻抗成像技术，来获取乳腺组织的阻抗分布图像。 本文首先对乳腺电阻抗成像技术的背景意义及发展现状进行了综述。接着详细推导了有限元方法中三棱柱单元分析的过程，并给出了圆柱模型的解析解公式。仿真中建立圆柱模型，分别使用解析方法和基于三棱柱单元的有限元方法计算正问题。通过数值解与解析解的比较，评估了FEM解的精确度，节点的电位误差低于3.57%。接着介绍了线性敏感矩阵法构造系统方程以及两种求解方程的方法，即TSVD和sLORETA方法。从仿真中的重构结果可知，sLORETA的结果更平滑些，，但是两种方法得到的区域内部电导率的空间分辨率都比较低。最后本文引入FOCUSS方法，研究了FOCUSS方法的理论及其计算步骤，分别以TSVD和sLORETA重构的电导率分布作为初始值，进一步使用FOCUSS方法提高了内部电导率的空间分辨率。
[Abstract]:Electrical impedance imaging is a new biomedical imaging technology. It can obtain the distribution of electrical conductivity in the target region by injecting current into the target area and then measuring the surface voltage. Based on the significant difference between the electrical conductivity of malignant tumor tissue and the healthy breast tissue or benign tumor tissue, the electrical impedance imaging technique is used to obtain the impedance distribution image of breast tissue. In this paper, the background significance and development status of electrical impedance imaging of mammary gland are reviewed. Then, the analysis process of triangular prism element in the finite element method is deduced in detail, and the analytical solution formula of the cylindrical model is given. In the simulation, the cylindrical model is established and the forward problem is calculated by using the analytical method and the finite element method based on the triangular prism element, respectively. The accuracy of the FEM solution is evaluated by comparing the numerical solution with the analytical solution. The potential error of the node is less than 3.57. Then the linear sensitive matrix method is introduced to construct the system equations and two methods to solve the equations, namely, TSVD and sLORETA methods. From the reconstruction results of simulation, the results of sLORETA are smoother, but the spatial resolution of the internal conductivity of the two methods is relatively low. Finally, the FOCUSS method is introduced to study the theory and calculation steps of the FOCUSS method. The conductivity distribution of TSVD and sLORETA reconstruction is taken as the initial value, and the spatial resolution of the internal conductivity is further improved by using the FOCUSS method.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R310
[Abstract]:Electrical impedance imaging is a new biomedical imaging technology. It can obtain the distribution of electrical conductivity in the target region by injecting current into the target area and then measuring the surface voltage. Based on the significant difference between the electrical conductivity of malignant tumor tissue and the healthy breast tissue or benign tumor tissue, the electrical impedance imaging technique is used to obtain the impedance distribution image of breast tissue. In this paper, the background significance and development status of electrical impedance imaging of mammary gland are reviewed. Then, the analysis process of triangular prism element in the finite element method is deduced in detail, and the analytical solution formula of the cylindrical model is given. In the simulation, the cylindrical model is established and the forward problem is calculated by using the analytical method and the finite element method based on the triangular prism element, respectively. The accuracy of the FEM solution is evaluated by comparing the numerical solution with the analytical solution. The potential error of the node is less than 3.57. Then the linear sensitive matrix method is introduced to construct the system equations and two methods to solve the equations, namely, TSVD and sLORETA methods. From the reconstruction results of simulation, the results of sLORETA are smoother, but the spatial resolution of the internal conductivity of the two methods is relatively low. Finally, the FOCUSS method is introduced to study the theory and calculation steps of the FOCUSS method. The conductivity distribution of TSVD and sLORETA reconstruction is taken as the initial value, and the spatial resolution of the internal conductivity is further improved by using the FOCUSS method.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R310
【参考文献】
相关期刊论文 前3条
1 李果;;一种基于MNLS解的迭代波达方向估计方法[J];重庆科技学院学报(自然科学版);2009年06期
2 路彦峰;刘建军;路洪艳;;圆柱、球坐标系下%溅怠
本文编号：2341375
本文链接：https://www.wllwen.com/yixuelunwen/swyx/2341375.html
