Fitzgerald Anthony J, Pickwell-MacPherson Emma, Wallace Vincent P
School of Physics, University of Western Australia, WA, Australia.
Electronic Engineering Department, Chinese University of Hong Kong, Hong Kong.
PLoS One. 2014 Jul 10;9(7):e99291. doi: 10.1371/journal.pone.0099291. eCollection 2014.
The aim of this work was to evaluate the capabilities of Debye theory combined with Finite Difference Time Domain (FDTD) methods to simulate the terahertz (THz) response of breast tissues. Being able to accurately model breast tissues in the THz regime would facilitate the understanding of image contrast parameters used in THz imaging of breast cancer. As a test case, the model was first validated using liquid water and simulated reflection pulses were compared to experimental measured pulses with very good agreement (p = 1.00). The responses of normal and cancerous breast tissues were simulated with Debye properties and the correlation with measured data was still high for tumour (p = 0.98) and less so for normal breast (p = 0.82). Sections of the time domain pulses showed clear differences that were also evident in the comparison of pulse parameter values. These deviations may arise from the presence of adipose and other inhomogeneities in the breast tissue that are not accounted for when using the Debye model. In conclusion, the study demonstrates the power of the model for simulating THz reflection imaging; however, for biological tissues extra Debye terms or a more detailed theory may be required to link THz image contrast to physiological composition and structural changes of breast tissue associated with differences between normal and tumour tissues.
这项工作的目的是评估德拜理论结合时域有限差分（FDTD）方法模拟乳腺组织太赫兹（THz）响应的能力。能够在太赫兹波段准确模拟乳腺组织将有助于理解乳腺癌太赫兹成像中使用的图像对比度参数。作为一个测试案例，该模型首先使用液态水进行了验证，模拟的反射脉冲与实验测量的脉冲进行了比较，结果吻合度很高（p = 1.00）。利用德拜特性对正常和癌性乳腺组织的响应进行了模拟，与测量数据的相关性对于肿瘤组织仍然很高（p = 0.98），而对于正常乳腺组织则较低（p = 0.82）。时域脉冲的部分显示出明显差异，这在脉冲参数值的比较中也很明显。这些偏差可能源于乳腺组织中脂肪和其他不均匀性的存在，而在使用德拜模型时并未考虑这些因素。总之，该研究证明了该模型在模拟太赫兹反射成像方面的能力；然而，对于生物组织，可能需要额外的德拜项或更详细的理论来将太赫兹图像对比度与乳腺组织的生理组成和与正常组织和肿瘤组织差异相关的结构变化联系起来。
