Bowman Tyler, El-Shenawee Magda, Campbell Lucas K
Department of Electrical Engineering, University of Arkansas, 3217 Bell Engineering Center, Fayetteville, AR 72701, USA.
Northwest Arkansas Pathology Associates, P. A., 390 E. Longview St. Fayetteville, AR 72703, USA.
Biomed Opt Express. 2016 Aug 30;7(9):3756-3783. doi: 10.1364/BOE.7.003756. eCollection 2016 Sep 1.
This work presents experimental and analytical comparison of terahertz transmission and reflection imaging modes for assessing breast carcinoma in excised paraffin-embedded human breast tissue. Modeling for both transmission and reflection imaging is developed. The refractive index and absorption coefficient of the tissue samples are obtained. The reflection measurements taken at the system's fixed oblique angle of 30° are shown to be a hybridization of and modes. The models are validated with transmission spectroscopy at fixed points on fresh bovine muscle and fat tissues. Images based on the calculated absorption coefficient and index of refraction of bovine tissue are successfully compared with the terahertz magnitude and phase measured in the reflection mode. The validated techniques are extended to 20 and 30 μm slices of fixed human lobular carcinoma and infiltrating ductal carcinoma mounted on polystyrene microscope slides in order to investigate the terahertz differentiation of the carcinoma with non-cancerous tissue. Both transmission and reflection imaging show clear differentiation in carcinoma versus healthy tissue. However, when using the reflection mode, in the calculation of the thin tissue properties, the absorption is shown to be sensitive to small phase variations that arise due to deviations in slide and tissue thickness and non-ideal tissue adhesion. On the other hand, the results show that the transmission mode is much less sensitive to these phase variations. The results also demonstrate that reflection imaging provides higher resolution and more clear margins between cancerous and fibroglandular regions, cancerous and fatty regions, and fibroglandular and fatty tissue regions. In addition, more features consistent with high power pathology images are exhibited in the reflection mode images.
这项工作展示了太赫兹透射和反射成像模式在评估切除的石蜡包埋人类乳腺组织中的乳腺癌方面的实验和分析比较。开发了透射和反射成像的模型。获得了组织样本的折射率和吸收系数。在系统固定的30°倾斜角下进行的反射测量显示为 模式和 模式的混合。在新鲜牛肌肉和脂肪组织的固定点上，用透射光谱对模型进行了验证。基于计算出的牛组织吸收系数和折射率的图像与反射模式下测量的太赫兹幅度和相位成功进行了比较。经过验证的技术扩展到安装在聚苯乙烯显微镜载玻片上的20微米和30微米厚的固定人类小叶癌和浸润性导管癌切片，以研究癌组织与非癌组织的太赫兹差异。透射和反射成像都显示出癌组织与健康组织之间有明显的差异。然而，在使用反射模式时，在计算薄组织特性时，吸收对由于载玻片和组织厚度偏差以及不理想的组织粘附而产生的小相位变化很敏感。另一方面，结果表明透射模式对这些相位变化的敏感度要低得多。结果还表明，反射成像提供了更高的分辨率，并且在癌性与纤维腺性区域、癌性与脂肪区域以及纤维腺性与脂肪组织区域之间有更清晰的边界。此外，反射模式图像中展现出了更多与高倍病理图像一致的特征。
