Dielectric Characterization of Human Breast Tissue

拟议研究的目的是进行一套全面的测量，以确定恶性，良性和正常乳腺组织在100 MHz至20 GHz宽频率范围内的介电特性。本研究的结果将是验证两个假设所需的基线数据：a)在微波频率下，正常乳腺组织和乳腺恶性病变的介电特性存在系统且显著的差异；b)在微波频率下，乳腺良性病变和乳腺恶性病变的介电特性存在系统且显著的差异。从这些测量得到的数据需要促进非侵入性、非电离微波技术的工程，以补充和增强目前用于乳腺癌检测和管理的早期检测、诊断和治疗技术。我们研究的长期目标是通过使用时空微波成像作为x射线乳房x光检查的补充来改善乳腺癌筛查。从拟议的研究中获得的数据将允许后续开发用于临床试验的实用微波乳房成像系统。具体目标是：1)严格校准和测试将与微波矢量网络分析仪一起使用的同轴针探头，以获得频率高达20 GHz的新鲜切除乳腺组织样品的介电常数和电导率。2)测量约500个乳腺活检标本和60个乳腺缩小标本在生理温度和水分含量下的介电特性。3)将测量的介电特性数据与每个乳腺活检和乳腺缩小标本的完整手术病理报告相关联；该数据库将包括脂肪和纤维腺正常乳腺组织，良性肿瘤和增生性病变，浸润性癌和原位癌。4)对测量的介电特性数据进行生物电磁色散分析，并评估观察到的对比（或缺乏对比）的生物物理机制。5)对测量数据进行统计分析，检验两种组织-介电对比假设。该研究将为未来所有与乳腺相关的0.1 - 20ghz微波技术的发展提供科学基础，无论是用于肿瘤检测、监测还是治疗。

The objective of the proposed research is to conduct a comprehensive set of measurements to determine the dielectric properties of malignant, benign, and normal breast tissues over a broad frequency range from 100 MHz to 20 GHz. The outcome of the proposed research will be the baseline data needed to test two hypotheses: a) there exists a systematic and significant contrast in the dielectric properties of normal breast tissue and malignant breast lesions at microwave frequencies, and b) there exists a systematic and significant contrast in the dielectric properties of benign breast lesions and malignant breast lesions at microwave frequencies. The data resulting from these measurements are needed to facilitate the engineering of non- invasive, non-ionizing microwave technology to complement and augment early detection, diagnostic, and treatment technologies presently employed in the detection and management of breast cancer. The long-term objective of our research is to improve breast cancer screening through the use of space-time microwave imaging as a complement to X-ray mammography. The data obtained from the proposed study will permit subsequent development of a practical microwave breast imaging system for clinical trials. The specific aims are: 1) To rigorously calibrate and test coaxial needle probes that will be used with a microwave vector network analyzer to obtain the dielectric permittivities and conductivities of freshly excised breast tissue samples for frequencies up to 20 GHz. 2) To measure at physiologic temperatures and moisture contents the dielectric properties of approximately 500 breast biopsy specimens and 60 breast reduction specimens. 3) To correlate the measured dielectric properties data with the complete surgical pathology reports for every breast biopsy and breast reduction specimen; the database will include fatty and fibroglandular normal breast tissue, benign tumors and proliferative lesions, and infiltrating and in situ carcinomas. 4) To conduct bio-electromagnetic dispersion analyses of the measured dielectric properties data and to assess the biophysical mechanisms for the observed contrasts (or lack thereof). 5) To conduct statistical analyses of the measured data to test the two tissue-dielectric-contrast hypotheses. This research will provide a scientific foundation for all future microwave technology development related to the breast in the 0.1 to 20 GHz range, whether for tumor detection, monitoring, or treatment.