Title :
Numerical analysis of microwave detection of breast tumours using synthetic focussing techniques
Author :
Nilavalan, R. ; Leendertz, L. ; Craddock, I.J. ; Preece, A. ; Benjamin, R.
Author_Institution :
Dept. of Med. Phys., Bristol Univ., UK
Abstract :
Microwave detection of breast tumours is a non-ionising and potentially low-cost and more certain alternative to X-ray mammography. Analogous to ground penetrating radar (GPR), microwaves are transmitted using an antenna array and the reflected signals, which contain reflections from tumours, are recorded. The work presented here employs a post reception synthetically focussed detection method developed for land mine detection (R. Benjamin et al., IEE Proc. Radar, Sonar and Nav., vol. 148, no.4, pp. 233-40, 2001); all elements of an antenna array transmit a broadband signal in turn, the elements sharing a field of view with the current transmit element then record the received signal. By predicting the path delay between transmit and receive antennas via any desired point in the breast, it is then possible to extract and time-align all signals from that point. Repeated for all points in the breast, this yields an image in which the distinct dielectric properties of malignant tissue are potentially visible. This contribution presents a theoretical evaluation of the breast imaging system using FDTD methods. The FDTD model realistically models a practical system incorporating wide band antenna elements. One major challenge in breast cancer detection using microwaves is the clutter arising from skin interface. Deeply located tumours can be detected using windowing techniques (R. Nilavalan et al., Electronics Letters, vol. 39, pp. 1787-1789, 2003); however tumours closer to the skin interface require additional consideration, as described herein.
Keywords :
biomedical imaging; cancer; electromagnetic wave reflection; electromagnetic wave transmission; finite difference time-domain analysis; mammography; medical image processing; microwave antenna arrays; microwave imaging; radar clutter; radar imaging; receiving antennas; skin; transmitting antennas; tumours; FDTD methods; X-ray mammography; antenna array elements; breast cancer; breast imaging system; breast tumours; broadband signal; deeply located tumours; field of view; ground penetrating radar; land mine detection; malignant tissue dielectric properties; malignant tissue image; microwave antenna array; microwave detection; numerical analysis; path delay prediction; post reception synthetically focussed detection method; receive antennas; received signal time-alignment; reflected signals; skin interface clutter; synthetic focussing techniques; transmit antennas; wide band antenna elements; windowing techniques; Breast tumors; Broadband antennas; Focusing; Ground penetrating radar; Microwave antenna arrays; Microwave theory and techniques; Numerical analysis; Radar antennas; Radar detection; Transmitting antennas;
Conference_Titel :
Antennas and Propagation Society International Symposium, 2004. IEEE
Print_ISBN :
0-7803-8302-8
DOI :
10.1109/APS.2004.1331866