Mechanical Engineering Department, Northeastern University, Boston, MA 02115, USA.
Electrical Engineering Department, Northeastern University, Boston, MA 02115, USA.
Sensors (Basel). 2018 Jan 25;18(2):342. doi: 10.3390/s18020342.
Accurate and early detection of breast cancer is of high importance, as it is directly associated with the patients' overall well-being during treatment and their chances of survival. Uncertainties in current breast imaging methods can potentially cause two main problems: (1) missing newly formed or small tumors; and (2) false alarms, which could be a source of stress for patients. A recent study at the Massachusetts General Hospital (MGH) indicates that using Digital Breast Tomosynthesis (DBT) can reduce the number of false alarms, when compared to conventional mammography. Despite the image quality enhancement DBT provides, the accurate detection of cancerous masses is still limited by low radiological contrast (about 1%) between the fibro-glandular tissue and affected tissue at X-ray frequencies. In a lower frequency region, at microwave frequencies, the contrast is comparatively higher (about 10%) between the aforementioned tissues; yet, microwave imaging suffers from low spatial resolution. This work reviews conventional X-ray breast imaging and describes the preliminary results of a novel near-field radar imaging mechatronic system (NRIMS) that can be fused with the DBT, in a co-registered fashion, to combine the advantages of both modalities. The NRIMS consists of two antipodal Vivaldi antennas, an XY positioner, and an ethanol container, all of which are particularly designed based on the DBT physical specifications. In this paper, the independent performance of the NRIMS is assessed by (1) imaging a bearing ball immersed in sunflower oil and (2) computing the heat Specific Absorption Rate (SAR) due to the electromagnetic power transmitted into the breast. The preliminary results demonstrate that the system is capable of generating images of the ball. Furthermore, the SAR results show that the system complies with the standards set for human trials. As a result, a configuration based on this design might be suitable for use in realistic clinical applications.
准确且早期的乳腺癌检测非常重要，因为它直接关系到患者在治疗过程中的整体健康状况及其生存机会。当前的乳腺成像方法存在不确定性，可能会导致两个主要问题：（1）漏诊新形成或较小的肿瘤；（2）假警报，这可能会给患者带来压力。马萨诸塞州综合医院（MGH）的一项最新研究表明，与传统的乳房 X 光摄影相比，使用数字乳腺断层合成术（DBT）可以减少假警报的数量。尽管 DBT 提供了图像质量的提升，但癌症肿块的准确检测仍然受到 X 射线频率下纤维腺体组织和受影响组织之间的低放射对比度（约 1%）的限制。在较低的微波频率区域，上述组织之间的对比度要高得多（约 10%）；然而，微波成像是以低空间分辨率为代价的。这项工作回顾了传统的 X 射线乳房成像，并描述了一种新型近场雷达成像机电系统（NRIMS）的初步结果，该系统可以与 DBT 融合，以协同方式结合两种模式的优势。NRIMS 由两个对极化的 Vivaldi 天线、一个 XY 定位器和一个乙醇容器组成，所有这些都是根据 DBT 的物理规格专门设计的。在本文中，通过（1）对浸入葵花籽油中的轴承球进行成像和（2）计算由于电磁功率传输到乳房而产生的热比吸收率（SAR），来评估 NRIMS 的独立性能。初步结果表明，该系统能够生成球的图像。此外，SAR 结果表明该系统符合人体试验设定的标准。因此，基于这种设计的配置可能适用于现实的临床应用。
