基于CST的乳腺癌组织介电常数成像探究

目的：研究乳腺癌组织的介电常数成像的可行性及成像效果,并初步确立合适的成像参数。方法：根据已有文献中正常乳房组织与乳腺癌组织介电常数的数据差异,利用CST微波工作室软件建立正常乳房组织、乳腺癌组织及原测量同轴探头仿真模型,通过改变癌变组织半径及在正常乳房组织中的深度这两个参数,得到不同条件下的散射参数,并将其转化为阻抗信息后进行成像,通过分别固定癌变组织半径和深度,对另一参数下得到的不同成像图形进行比较分析,最终确定扫描成像的最优分辨率及深度。结果：在0.5 GHz-9.5 GHz频段,对本文所建立的乳腺癌组织模型进行介电常数成像可以得到清晰的成像图像,其分辨率为1 mm;其中,阻抗值实部的成像效果要明显优于阻抗值虚部的成像效果,在频率为5.89 GHz时,最佳的成像参数为：乳腺癌组织半径r=2 mm,距正常乳房组织表面深度h=1 mm。结论：本文分析了乳房X线照相术与超声检测的优缺点,并对乳腺癌组织仿真模型进行介电常数成像,成像结果具有较高的分辨率,验证了介电常数成像的可行性,为乳腺癌组织检测提供了新的思路。

Exploration of Imaging of Dielectric Constant of Breast Tumor Tissue Based on CST Microwave Studio

Objective： To study the feasibility and effect of dielectric constant imaging of breast tumor tissue, and determine proper imaging parameters. Methods： On the basis of data differneces of dielectric constant between normal and tumor breast tissue in existing literatures, the simulation model of normal breast tissue, breast tumor tissue and original coaxial probe was established by CST microwave studio. According to changing the two parameters, namely the radius of tumor tissue and the depth in normal breast tissue, scattering parameters on different conditions were obtained. Then the optimal resolution and depth of scan imaging were determined ultimately by fixing the tumor radius or depth of tissue tumor, contrasting and analyzing the images of impedance with the change of another parameter, while the impedance were transformed from scattering parameter. Results： The presented model of breast tumor tissue can obtain clear images of dielectric constant from 0.5 GHz to 9.5 GHz, while the resolution is lmm. Compared by the imaginary part of impedance,the imaging result of the real part of impedance is significantly better. And optimal imaging parameters, radius r and depth h of breast tumor tisssue, are 2 mm and lmm respectively at the frequency of 5.89 GHz. Conclnsions：The presented paper analyzed the advantages and disadvantages of mammography and ultrasound detection respectively. Images of dielectric constant of the presented human breast tumor tissue simulation model have a high resolution, which proves the feasibility of dielectric constant imaging and may provide a novel way of probing breast tumor in the future.