Abstract
Early breast cancer detection can save the women infected by malignant tumors. Microwave imaging has recently been proposed for detecting small malignant breast tumors at early stages. This type of cancer is the top-most cause of death among women due to malignant tumors. The detection of early-stage tumors in the breast by microwave imaging is challenged by both the moderate endogenous dielectric contrast between healthy and malignant glandular tissues and the spatial resolution available from illumination at PLFURZDYHIUHTXHQFLHV 7KHKLJKHQGRJHQRXVGLHOHFWULFFRQWUDVWEHWZHHQDGLSRVHDQG¿EURJODQGXODUWLVVXH VWUXFWXUHVLQFUHDVHVWKHGLI¿FXOW\RIWXPRUGHWHFWLRQGXHWRWKHKLJKG\QDPLFUDQJHRIWKHFRQWUDVWIXQFWLRQ to be imaged and the low level of signal scattered from a tumor relative to the clutter scattered by normal WLVVXH VWUXFWXUHV 0LFURZDYH LQYHUVH VFDWWHULQJ WHFKQLTXHV XVHG WR HVWLPDWH WKH FRPSOHWH VSDWLDO SUR¿OH of the dielectric properties within the breast, have the potential to reconstruct both normal and cancerous tissue structures. However, the ill-posedness of the associated inverse problem often limits the frequency of microwave illumination to the ultra high frequency (UHF) band within which early-stage cancers have sub-wavelength dimensions. This review presents the research status of microwave imaging for malignant tumor detection. Many methods have been used, i.e., active, passive, and hybrid. However, it is important to remember that, in addition to microwave imaging, several alternative breast cancer detection modalities are actively being pursued, including optical imaging methods.
