基于超宽带天线及MRI导出乳房模型的乳腺肿瘤检测仿真

发布时间：2018-06-15 13:39

本文选题：乳腺肿瘤 + 时域有限差分　；参考：《天津大学》2014年硕士论文

【摘要】：乳腺癌现已成为威胁女性健康的第一大恶性肿瘤疾病。早期发现有助于患者及时前往医院接受合理治疗,以提高存活率。目前作为最常用的检测手段,钼靶X射线乳房照相术能够较准确地检测肿瘤。然而,该技术有许多缺点,如电离辐射、对乳房挤压等,其本身可能增加罹患癌症的几率且给女性带去身心上的痛苦,因此该技术不能作为一种经常性使用的手段。最近十几年,超宽带微波乳腺肿瘤技术被提出并得到广泛研究。该技术的优点在于安全无辐射、便宜易集成携带、对乳房无压迫等,能够作为一种辅助常规定期自查手段。目前世界上有多个课题组致力于该技术的研究开发。在许多早期模拟研究中,检测实验未考虑天线结构的影响,为了简化仿真而选择利用点源代替天线。且使用的乳房模型通常是较为简单的矩形、半球型等模型,而真实的乳房外形轮廓、内部组织分布都更复杂。为了更加真实地模拟电磁波在现实环境的传播,有必要将天线结构以及形态学上真实的乳房模型加入到仿真系统中。本文首先基于FDTD算法完成了电磁场仿真,并使用集总元件技术将阻性电压源加入到天线馈电端口,完成了对超宽带天线建模仿真。本文共对两款天线进行了仿真模拟,其中一款工作在空气中,另一款工作在与皮肤接触环境中。接下来利用第二款天线组成阵列加入到乳腺肿瘤检测系统仿真中,并将仿真得到信号使用成像算法进行处理,验证了成像算法的适用性。本文基于临床MRI医学影像导出了三种乳房模型。其一为组织分块模型,基于该模型,本文研究了乳腺多少对最终成像效果的影响,并提出了一种检测多发肿瘤的方法。其二为应用于FDTD仿真的二维模型,该模型更加真实地模拟了乳房外形轮廓以及内部乳房组织分布情况。其三为应用于FDTD的三维模型,该模型是通过对MRI图进行插值处理后,导出对应MRI-FDTD二维模型切片并堆叠得到。最后本文将MRI-FDTD二维、三维模型耦合加入到FDTD程序中,并通过仿真实验验证了成像算法的适用性。
[Abstract]:Breast cancer has become the first major malignant tumor disease threatening women's health. Early detection can help patients to go to hospital in time to receive reasonable treatment to improve survival rate. At present, mammography is the most commonly used method to detect tumor accurately. However, the technique has many disadvantages, such as ionizing radiation, breast compression and so on, which in itself may increase the risk of cancer and bring mental and physical pain to women, so it cannot be used as a means of regular use. In recent years, ultra-wideband microwave (UWB) technique for breast neoplasms has been proposed and widely studied. The advantages of this technique are that it is safe and radiation free, cheap and easy to carry, no compression to the breast, and can be used as a supplementary routine self-examination method. At present, there are many research groups in the world dedicated to the research and development of this technology. In many early simulation studies, the effect of antenna structure has not been considered in the detection experiment. In order to simplify the simulation, the point source is chosen to replace the antenna. The mammary models used are usually simple rectangular and hemispherical models, while the actual breast contour and internal tissue distribution are more complicated. In order to simulate the propagation of electromagnetic wave in real environment more realistically, it is necessary to add the real mammary model of antenna structure and morphology to the simulation system. In this paper, the electromagnetic field simulation is completed based on FDTD algorithm, and the resistive voltage source is added to the antenna feed port using lumped component technology, and the UWB antenna modeling and simulation is completed. In this paper, two antennas are simulated, one working in air and the other in contact with skin. Then the second antenna array is added to the simulation of breast tumor detection system, and the simulation signal is processed by the imaging algorithm, which verifies the applicability of the imaging algorithm. Three breast models were derived based on clinical MRI images. Based on the model, the influence of how much mammary gland has on the final imaging effect is studied, and a method to detect multiple tumors is proposed. The second is a two-dimensional model which is applied to FDTD simulation. The model can simulate the outline of breast and the distribution of breast tissue more realistically. The third is the 3D model applied to FDTD. The model is obtained by interpolating the MRI image and deriving the corresponding two-dimensional MRI-FDTD model slicing and stacking. Finally, two and three dimensional models of MRI-FDTD are coupled into the FDTD program, and the applicability of the imaging algorithm is verified by simulation experiments.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R737.9;TN822.8

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