Researchers at Carnegie Mellon University's College of Engineering are working to find new ways to monitor breast cancer in patients.

Second-year PhD student Constance Robbins is working with Jana Kainerstorfer, assistant professor of biomedical engineering, to develop imaging technology to noninvasively show how lesions can change over time. James Antaki, professor of biomedical engineering, is a collaborator on the project.

"We're not trying to replace mammograms," Robbins said. "If you have results that are inconclusive, but there's not high enough of a risk to justify a biopsy right away, then that would be something we could use this device for." Breast cancer is the most prevalent non-skin cancer among women. Most of the advocated procedures for diagnosis and monitoring — mammograms, breast ultrasounds, breast biopsies, breast MRIs — require expensive equipment. It is not feasible for these procedures to be performed regularly, or in underdeveloped areas where access to equipment may be rare.

Robbins' effort builds on the work of Molly Blank, who graduated in 2016 with a doctorate in biomedical engineering. Blank, now a design lecturer in the Department of Bioengineering at the University of Washington, created Palpaid, a small handheld device that leverages the stiffness of the lesion in comparison to the surrounding tissue. When pressed against the breast, the device's flexible, reflective lens forms around the stiff tissue and captures a topographic image of the deformation, which could then be examined for information on size, shape, stiffness and location.

Robbins is taking the idea one step further, hoping to measure not only mechanical properties but also any abnormal or excessive formations of blood vessels. To accomplish this, she is using an imaging method called spatial frequency domain imaging (SFDI), in which different patterns of light are shown on an area to extract information. The variations in reflection show how much light the tissue can absorb, which in turn depends on the concentration of hemoglobin in the tissue.

"We're trying to measure the absorption coefficient of the stiff tissue as well as the healthy tissue around it," Robbins said. "But if the lesion is too deep, we won't be able to detect it - that's why we use compression, to decrease the distance from the lesion to our sensors."

By compressing the tissue and essentially pushing the lesion closer toward the surface of the breast, the light can penetrate further into the tissue, and the device can get a better read on the lesion's blood content.

Robbins presented her research at the SPIE Photonics West Conference, a conference dedicated to optics, earlier this year.

Blank said that by tracking not only size and shape of breast lumps but now also the extent of blood flow to the area, the technology that Collins is pursuing could provide a more definitive assessment of a woman's risk for cancer non-invasively. She said that the innovation is especially important innovation for younger women who have denser breast tissues that are more difficult to assess with mammography.