Microwave Breast Imaging Using a Dry Setup

Abstract

The paper demonstrates for the first time, both numerically and experimentally, the feasibility of radar-based microwave imaging of anthropomorphic heterogeneously dense breasts in prone position, requiring no immersion liquid. The dry, contactless approach greatly simplifies the setup, favors patient comfort, and further avoids lengthy sanitation procedures after each exam. We use a radar-type technique with the antennas distributed in cylindrical configuration around the breast phantom. The reflectivity map is reconstructed using a wave-migration algorithm in the frequency domain. The paper presents new developed strategies to cope with the challenges of a dry setup, namely increased skin artifact due to the concomitant absence of matching liquid and non-uniform breast shape. We propose an iterative and adaptive algorithm based on singular value decomposition that effectively removes the skin backscattering under the above conditions. It is compatible with automatic processing, and computationally fast. One of its inputs is the breast three-dimensional surface information, and its distance to the antennas, all obtained automatically from a proposed low-cost procedure based on a webcam. The imaging method is reasonably resilient to the presence of fibroglandular tissues, and to uncertainties of tissue permittivity. Another tackled challenge is the miniaturization of the antenna in air, which is achieved with an optimized balanced antipodal Vivaldi of the same size as counterparts used in dense immersion liquids. Finally, all the building blocks are combined to demonstrate experimentally the overall dry system performance, with very good detection of the tumor at three different positions in the breast, even in low contrast scenarios.

Development of an Anthropomorphic Phantom of the Axillary Region for Microwave Imaging Assessment

“…We may consider that this response is sufficiently high, given that commercial VNAs have a dynamic range of a least 90 dB, which would be sufficient to detect a useful response of the ALNs. In addition, the magnitude of such response is comparable to the one experimentally obtained for breast tumor imaging in Reference [ 53 ], where the authors successfully detected the tumor in the correct position.…”

“…Two main reasons motivated this choice: the first is that the shape of the underarm hinders its immersion and the usability of the setup; the second is that the liquid may raise concerns about hygiene between examinations. Some groups working on medical MWI have demonstrated the feasibility of such a dry approach [ 52 , 53 ], including some authors of this paper.…”

A Simulation-Based Methodology of Developing 3D Printed Anthropomorphic Phantoms for Microwave Imaging Systems

“…As defined in the framework of the EMERALD project, the manufacturing process used to build up accurate ultra-wideband (UWB) phantoms has to be easily reproducible by an electrical engineer in a non-specific environment without extreme precautions, and to some extent at low cost. The specificity of the GeePs-L2S breast phantom and those suggested in our previous and current works on the head [ 19 , 32 ], breast [ 13 , 33 ], and thorax [ 34 , 35 ] phantoms, has been confirmed by the work of [ 14 , 15 , 16 , 17 , 18 ] and [ 36 , 37 , 38 , 39 ]. These phantoms composed of several 3D printed cavities are filled up with liquid mixtures made for example of Triton X-100 (TX-100, a non-ionic surfactant) and salt water, the concentrations are numerically adjusted so that the dielectric properties are close to the reference values over a wide frequency range.…”

“…Burfeindt et al, have given the scientific community access to an STL file of a breast phantom [ 12 ] made of a unique cavity. This gave rise to the 3 cavities GeePs-L2S breast phantom [ 13 ] which is designed and developed by using CAD software from the STL file in open access and whose printed form was in turn shared within the framework of COST TD1301 MiMed to test several microwave imaging systems in development [ 14 , 15 , 16 , 17 , 18 ].…”

An Overview of Microwave Imaging for Breast Tumor Detection

“…Again in 2019, Manoufali et al proposed three implantable antennas [114] which were used to image the cerebrospinal fluid of piglets, and the antennas were able to sense the variations of the dielectric properties correctly. Felicio et al assembled a dry contactless imaging setup without the use of any immersion liquid [115]. The radar-based setup based on wave-migration algorithm added to patient comfort and avoided sanitation procedures after each imaging session.…”