Breast cancer tumour detection using microwave radar techniques

A breast cancer detection technique using multi-static radar is proposed herein. Images of a breast tumour are produced using this technique, with backscatter data. A wideband antenna design suitable for a breast cancer detection system is also described. Practical measurements are performed using a network analyser and a pair of antennas that are used to simulate an array. These initial images demonstrate the successful detection of a tumour phantom immersed in a liquid phantom with similar dielectric properties as the breast tissues

Breast tumour detection using a flat 16 element array

A new experimental prototype of a breast cancer detection technique using real aperture multi-static radar is presented. The system comprises a fully-populated 16 element flat array and an associated system to switch between different transmit and receive elements. 3D images are produced using backscatter signals from a synthetic breast phantom. After suppression of skin reflections, initial images demonstrate the successful detection of 4-mmdiameter tumours

Microwave detection of breast tumours

Copyright @ 2003 European Bioelectromagnetics Association

Numerical analysis of microwave detection of breast tumours using synthetic focussing techniques

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

Wideband microstrip patch antenna design for breast cancer tumour detection

A patch antenna is presented which has been designed to radiate into human breast tissue. The antenna is shown by means of simulation and practical measurement to possess a wide input bandwidth, stable radiation patterns and a good front-to-back ratio. Consideration is also given to its ability to radiate a pulse, and in this respect it is also found to be suitable for the proposed application

Experimental investigation of real aperture synthetically organised radar for breast cancer detection

Breast cancer is the most common cancer in woman, and early detection increases the likelihood of successful treatment and long-term survival screen film mammography is currently the most effective method for detecting breast tumours, however this technique suffers from relatively high false negative and positive detection rates, and it involves uncomfortable compression of the breast. This paper presents the experimental investigation of real aperture synthetically organised radar for breast cancer detection. The work presented herein originated as a theoretical study employing FDTD models. This contribution presents subsequent experimental validation using a mechanically-scanned 2 element antenna array and a breast phantom consisting of synthetic biological materials

A wideband planar antenna for in-body imaging

Breast cancer is the most common cancer in women. X-ray mammography is currently the most effective detection technique, however it suffers from a relatively high missed- and false-detection rates, involves uncomfortable compression of the breast and also entails exposure to ionizing radiation. Microwave detection of breast tumours is a potential non-ionising alternative being investigated by a number of groups. In these microwave-based systems, in a similar fashion to ground penetrating radars, microwaves are transmitted from an antenna or antenna array, and the received signals, which contain reflections from tumours, are recorded and analysed. A pre-requisite for all of these systems is a suitable antenna. This contribution presents in detail for the first time, an inexpensive, wideband, planar antenna design, specifically designed to radiate into breast tissue

Evaluation of Two Approaches for Breast Surface Measurement Applied to a Radar-Based Imaging System

Locating the surface of an object, in this case the breast, is an important first step in many imaging situations; this surface information may be a necessary part of the reconstruction, it may be needed for the cancellation of the surface reflection, or (as herein) it may be needed as a preparatory step before imaging. This paper presents two complementary approaches developed for the purpose of surface localisation. The proposed approaches are evaluated using data from both phantom measurements and volunteer scans

Subclinical Magnetic Resonance Imaging Markers of Cerebral Small Vessel Disease in Relation to Office and Ambulatory Blood Pressure Measurements

Background: Twenty-four-hour and nighttime blood pressure (BP) levels are more strongly associated with cardiovascular risk than office or daytime BP measurements. However, it remains undocumented which of the office and ambulatory BP measurements have the strongest association and predictive information in relation to the presence of type I, or arteriolosclerosis type, cerebral small vessel diseases (CSVD). Methods: A subset of 429 participants from the Maracaibo Aging Study [aged ≥40 years (women, 73.7%; mean age, 59.3 years)] underwent baseline brain magnetic resonance imaging (MRI) to visualize CSVD, which included log-transformed white matter hyperintensities (log-WMH) volume and the presence (yes/no) of lacunes, cerebral microbleeds (CMB), or enlarged perivascular spaces (EPVS). Linear and logistic regression models were applied to examine the association between CSVD and each +10-mmHg increment in the office and ambulatory systolic BP measurements. Improvement in the fit of nested logistic models was assessed by the log-likelihood ratio and the generalized R 2 statistic. Results: Office and ambulatory systolic BP measurements were related to log-WMH (β-correlation coefficients ≥0.08; P \u3c 0.001). Lacunes and CMB were only associated with ambulatory systolic BP measurements (odds ratios [OR] ranged from 1.31 [95% confidence interval, 1.10-1.55] to 1.46 [1.17-1.84], P ≤ 0.003). Accounted for daytime systolic BP, both the 24-h (β-correlation, 0.170) and nighttime (β-correlation, 0.038) systolic BP measurements remained related to log-WMH. When accounted for 24-h or daytime systolic BP levels, the nighttime systolic BP retained the significant association with lacunes (ORs, 1.05-1.06; 95% CIs, ≥1.01 to ≤ 1.13), whereas the 24-h and daytime systolic BP levels were not associated with lacunes after adjustments for nighttime systolic BP (ORs, ≤ 0.88; 95% CI, ≥0.77 to ≤ 1.14). On top of covariables and office systolic BP, ambulatory systolic BP measurements significantly improved model performance (1.05% ≥ R 2 ≤ 3.82%). Compared to 24-h and daytime systolic BP, nighttime systolic BP had the strongest improvement in the model performance; for WMH (1.46 vs. 1.05%) and lacunes (3.06 vs. ≤ 2.05%). Conclusions: Twenty-four-hour and nighttime systolic BP were the more robust BP measurements associated with CSVD, but the nighttime systolic BP level had the strongest association. Controlling ambulatory BP levels might provide additional improvement in the prevention of CSVD