What is the Future of Microwave Technology in Diagnostic Imaging?

Researchers at the Cancer Imaging and Radiobiology Research Program (CIR) at Dartmouth-Hitchcock's Norris Cotton Cancer Center study and test new ways to get good images using techniques that exploit different properties of tissue. This research program includes a collaborative team of engineers, family physicians, oncologists, and radiologists.

Microwave imaging has been shown reliable in detect breast tumors

One area we are exploring is microwave technology: the same basic technology used in microwave ovens can be used to create an image of breast tissue. By sending very low levels (1,000 times less than a cell phone) of microwave energy through tissue, researchers can form a three-dimensional image. These images capture the dielectric properties—electrical conductivity and permittivity (electrical resistance)—of the tissue, which translates into detecting anomalies, such as tumors or other aberrations.

Professor of engineering Paul Meaney has been working on microwave engineering for more than 15 years, primarily with Keith Paulsen, the co-director of the CIR, and also the Robert A. Pritzker Professor of Biomedical Engineering; professor of radiology at the Geisel School of Medicine at Dartmouth; and director of the Dartmouth Advanced Imaging Center at Dartmouth-Hitchcock Medical Center.

Their work together has revealed that microwave imaging is not just for soft tissue, and it's not just for detecting tumors. They have determined that microwave technology can produce images of bones that correlate to other more commonly used techniques that measure bone density, like X-ray, ultrasound, or CT. Their work was published in the journal IEEE Transactions on Biomedical Engineering, and it's the first study to use microwave technology to get images of the calcaneus bone, or heel, in humans. (The heel region is comparable to the allotted breast size. With some minor modifications to the microwave image system Dartmouth scientists constructed to study breasts, they were able to move from investigating soft tissue to looking at heel bones.)

Below, Paulsen describes breast-cancer imaging techniques that go beyond mammography: