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A H Barrett

Publications and source records attributed to A H Barrett.

5 recordsLinked to original sources

Microwave thermography in the detection of breast cancer.

Microwave thermography, a method of sensing subcutaneous temperatures, was used in a breast cancer detection study of about 5,000 female patients. The data were taken at wavelengths of 9.1 and 23 cm. Microwave thermography at 23 cm has true-positive and true-negative detection rates of 0.8 and 0.6, respectively, comparable to those of infrared thermography (0.7) and inferior to those of xeromammography (0.9). However, a potential advantage results if microwave and infrared thermography are used together for screening, and if mammography is used only for follow-up on those patients who were positive on either the microwave or the infrared thermograms. It is then possible to obtain true-positive and true-negative detection rates of 0.9 and 0.9, respectively, while only half the number of patients need be subjected to x-rays.

Breast Neoplasms↗

Microwave thermography: principles, methods and clinical applications.

We review the physical principles, method of operation, measurement limitations, and potential medical applications of microwave thermography. We present detailed results of a study of breast cancer detection at 1.3 and 3.3 GHz, including the dependence of detection rates on microwave frequency, time, tumor depth, and tumor size. At 1.3 GHz, microwave thermography detects breast cancer as well as infrared thermography (true-positive rate = 0.76 when true-negative rate = 0.63). When the two methods are combined, the true-positive rate increases by about 0.1 over that of either method alone.

Breast Neoplasms↗

Subcutaneous temperatures: a method of noninvasive sensing.

A new method of noninvasive sensing of the subsurface temperature distribution in human and animal tissue is described. Thermal radiation emitted from subsurface depths of several centimeters can be detected with microwave receivers. Temperature sensitivity of order 0.1 degree C and spatial resolution of approximately 1 by 2 centimeters have been obtained. Measurements demonstrating the technique, with feline and human tissue, are reported. A potential medical application is the detection of subsurface thermal anomalies such as malignant tumors and regions of vascular insufficiency.

Animals↗

Microwave thermography: a method of detecting subsurface thermal patterns.

A discussion has been given of the principles and techniques of microwave thermography. The method is analogous to infrared thermography in that it detects thermal radiation emitted by the body. It differs in that it is sensitive to temperatures several centimeters beneath the skin surface and has coarser spatial resolution. Results are shown of successful attempts to detect subsurface thermal gradients in feline and human tissue. Planned clinical evaluation is described.

Animals↗