Microwaves May Provide Early Detection Of Bre...( the breast tissues. A complete micro...),Health

A complete microwave tumor-detection system will consist of a sensor and a computer processor. The microwave sensor will be a small flat panel containing an array of miniature antennas placed on the surface of the breast. "We can focus the microwave signal within the breast, and the entire breast can be electronically scanned under software control to create a three-dimensional microwave image," Bridges said.

A laboratory prototype of the microwave sensor was built almost entirely with off-the-shelf components. The device was successfully tested on a "phantom" -- a simulated breast consisting of materials that share key microwave properties of normal breast tissues. A tiny simulated tumor was embedded within the breast phantom and was located using the microwave sensor. Phantoms are well-established proving grounds for new techniques and are used for routine calibration of existing mammography equipment. The microwave sensor has not yet been tested on humans.

The breast-phantom tests showed that the laboratory prototype sensor could easily detect one-quarter-inch simulated tumors embedded about 1.5 inches deep. With modest equipment improvements, even smaller tumors at least two inches deep could be detected. These results were consistent with those developed by the supercomputer simulations. The results also suggest that microwaves can detect some early-stage tumors that are invisible to X-ray mammography. X-rays rely on the presence of tiny calcium deposits within tumors to sense tumors too small to cast a shadow; however, not all early-stage tumors contain such calcium deposits. On the other hand, microwaves do not require calcium deposits for detection. In the case of microwaves, a tumor's response is generated by its entire cross section.

"A conventional X-ray mammogram is literally a shadowgram," Taflove explained. "As X-rays pass through the compressed breast, shadows appear on the X-ray film. The shadows represent the pro
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Contact: Bill Burton
b-burton@nwu.edu
847-491-3115
Northwestern University
28-Oct-1998