| Popis: |
A microwave radiometer at 3.3 GHz was used to map thermal radiation from the human body. As is true of infrared thermography, regions of high or low brightness may be associated with pathological conditions, such as malignant tumors or vascular blocks. Microwave radiometry has coarser spatial resolution than infrared thermography (∼cm2 rather than ∼mm2 ), but greater sensitivity to deep tissue temperature (∼cm rather than ∼0.1 mm) because of the relative transparency of tissues at microwave frequencies. Temperature resolution is comparable (0.1 °C). Clinical application to detection of breast cancer was attempted with a dielectric-filled waveguide antenna and a point-by-point mapping technique with over 2000 patients, including 26 with cancer. True-positive and true-negative rates of detection in excess of 70% were found. These rates are comparable with that obtained by infrared thermography but are inferior to xero-mammographic rates of detection for the same set of patients. Combining the microwave and infrared thermographic data, the true-positive detection rate becomes 96% based on 26 cases. |
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