Preliminary imaging results and SAR analysis of a microwave imaging system for early breast cancer detection

An Investigation using Specific Absorption Rate Analysis to Diagnose Early-Stage Breast Tumor using UWB Antenna

AIMS

This study aimed to focus on the detection of early-stage breast tumor and its location.

BACKGROUND

Breast Cancer is the disease with the highest rate of progression and mortality among women. Due to breast cancer/tumors, the risk of mortality for women has risen exponentially. Between 2006 and 2010, women died from carcinoma at a rate of 123.8 cases per lakh, well ahead of the 2020 deadline for breast cancer. This problem may be also overcome by early identification of the tumor using different detection procedures like X-ray mammography, computerized tomography, ultrasound imaging technique, positron emission tomography (PET), magnetic resonance imaging (MRI), and microwave imaging [1]-[5]. Researchers have carried out multiple studies in these areas.

OBJECTIVE

To detect early-stage breast tumor and its location using SAR analysis.

METHODS

The major dielectrical difference between cancerous breast tissues and normal tissues in this technique is the microwave frequency range. The term Specific absorption rate (SAR) describes the amount of energy that is absorbed (W/Kg) in the breast tissue. This segment illustrates the usefulness of diagnosing the tumor position in the breast by means of maximum SAR value coordinates. Changes in breast and tumor size are important for the risk of diagnosis. The power absorbed in connecting with a normal breast and a tumor breast is measured and equivalent for different breast masses. The maximum SAR is also analyzed at distinct tumor locations at various frequency ranges.

RESULTS

It is observed that max SAR coordinates are very close to the actual tumor location. So, the maximal value of SAR coordinates indicates the existence of tumor in the breast phantom.

CONCLUSION

The simulated data above strongly suggests that the Max SAR values were higher in the breast phantom with tumor as compared to the breast without tumor. With different tumor radius (3 mm and 5 mm) analyzed with different resonant frequencies like 3GHz, 4GHz, and 5GHz at actual tumor locations of (0, 0, 35). Even though a model representing the real properties of breast tissue is required to assess the validation of any imaging process, so the real-time development of equivalent breast phantom and its execution is needed.

Preliminary Results of a New Auxiliary Mechatronic Near-Field Radar System to 3D Mammography for Early Detection of Breast Cancer

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.