Two-dimensional FDTD analysis of a pulsed microwave confocal system for breast cancer detection: fixed-focus and antenna-array sensors

TLDR

Microwave imaging exploits the translucent nature of normal breast tissue and the high dielectric contrast between malignant tumors and surrounding normal tissue, offering an alternative to X‑ray and ultrasound. The study investigates a novel focused active microwave system for breast tumor detection. The authors employed a pulsed confocal microwave system with time‑gating and performed a 2‑D FDTD simulation using published dielectric properties to model tumor detection. The FDTD simulations showed that tumors as small as 2 mm could be robustly detected amid tissue heterogeneity, with a lateral spatial resolution of about 0.5 cm.

Abstract

A novel focused active microwave system is investigated for detecting tumors in the breast. In contrast to X-ray and ultrasound modalities, the method reviewed here exploits the breast-tissue physical properties unique to the microwave spectrum, namely, the translucent nature of normal breast tissues and the high dielectric contrast between malignant tumors and surrounding lesion-free normal breast tissues. The system uses a pulsed confocal technique and time-gating to enhance the detection of tumors while suppressing the effects of tissue heterogeneity and absorption. Using published data for the dielectric properties of normal breast tissues and malignant tumors, we have conducted a two-dimensional (2-D) finite-difference time-domain (FDTD) computational electromagnetics analysis of the system. The FDTD simulations showed that tumors as small as 2 mm in diameter could be robustly detected in the presence of the background clutter generated by the heterogeneity of the surrounding normal tissue. Lateral spatial resolution of the tumor location was found to be about 0.5 cm.