Multistatic radar: first trials of a new breast imaging modality

None of the current breast imaging modalities are perfect. Mammography has quite a low sensitivity, uses ionising radiation and is uncomfortable. Ultrasound has better sensitivity, is cheap, but is user dependent and not very good for screening. Magnetic resonance imaging has good sensitivity but is expensive. Positron emission tomography is extremely expensive. Other modalities have been tested, such as thermal imaging, red light imaging and elastography. We present a new modality - microwave RADAR imaging.

This uses electromagnetic radiation in the gigahertz range (similar to a mobile phone, but much lower power). Research has been going on for many years using single emitters and antennae, which has proven the concept but was unable to produce high definition images. The breakthrough came with using technology developed for land mine radar detection - multistatic arrays.

The third generation imaging apparatus uses 31 microwave emitters arranged in a hemisphere in which the breast sits in a prone table system. This gives 435 different pathways through the breast, which go into a network analyser and then are translated into a three-dimensional image for viewing and manipulation.

We have now done the initial trials with first use in humans; 160 women with lesions have been scanned and are being compared with mammography and ultrasound. The results are encouraging; most lesions are visible and it has a good ability to distinguish between benign and malignant lesions with a modality that is quicker, cheaper, safer and more comfortable.

Pictures of the apparatus and images produced will be shown.