Pratt Fellow Bresslour Builds Microwave-Based Breast Imaging Device

February 1, 2007

BresslourPratt Undergraduate Research Fellow Elan Bresslour isn't satisfied with traditional X-ray mammography, the primary imaging method for breast cancer screening. In the lab of electrical and computer engineering professor Qing Liu, she is applying her engineering skill toward the development of a device with the potential to offer a valuable alternative: an imager based on less harmful, and perhaps more sensitive, microwave radiation.

"Now, mammograms are the number one test for breast cancer," said Bresslour, an ECE major from Randolph, N.J. "But there are problems. Mammograms rely on ionizing radiation, which can be damaging, and have a high false positive ratio.

"Microwave imaging works by scattering radiation based on differences in tissue properties, including its permittivity and conductivity. There is a big difference in such properties between normal and malignant tissue, which should translate into better distinction between a tumor and a benign cyst."

Professor Liu had already developed computer software capable of integrating data on the scattering of microwaves to produce an image, a computationally intensive process. But he needed someone to design the imaging hardware itself, Bresslour said.

The device she is working to build consists of an imaging chamber including four pyramid-shaped panels. Each panel includes an array of 16 antennas hooked to a multiplexor. The specially-designed multiplexors allow the antennas to work in sequence, she explained, each taking turns transmitting a signal while the rest receive the scattered radiation and transmit the data back to a computer.

Bresslour has already tested her prototype device to image mock tumors -- actually two centimeter clay balls -- to test her imaging technology. She said the microwave imager can capture all the data needed to produce an image in as little as two minutes.

"We got an image, but it’s imperfect," she said.

She and others in the Liu lab are now working on a second version of their imaging chamber, designed to capture clay or a breast surrounded by liquid, instead of air. Such a design should help to reduce the amount of microwave radiation scattered when it hits the surface of the skin, before reaching a potential tumor within, Bresslour explained.

Such a design might also be more comfortable, she added.

"We envision that a woman would lie stomach down on a table with a hole for the fluid-filled chest imaging chamber. The liquid could be heated to room temperature."

Bresslour said microwave imaging might have yet another bonus: it is expected to cost less than X-ray mammography.

Bresslour discovered engineering when, as a junior in high school, she took joint courses in physics and engineering along with 20 other boys. She enrolled at Duke for its engineering program and "good social atmosphere." Her interest in imaging was cemented during a summer working in a Duke Medical Center laboratory that specializes in functional magnetic resonance imaging (fMRI), which relies on another form of non-ionizing radiation to detect brain activity in real time. Bresslour, who is the vice president of Duke's Society of Women Engineers, plans to work for a medical device company after graduation before going back to graduate school.