Electrical impedance measurements exploit the
differences in the electrical properties of materials to detect
inhomogeneities. Electrodes placed on the surface of an object are used to
determine the electrical characteristics of the volume of that object. In vitro
studies have discovered a difference of three times or more in electrical
conductivity and permittivity between healthy and cancerous tissue. For this
reason, theory suggests that electrical impedance imaging may be able to detect
certain types of cancer. This research group hopes
to detect breast cancer using the latest in the series of ACT instruments, ACT
4.
Currently being used to acquire patient data,
the ACT 4 instrument is a 72 channel device, capable of operating at multiple
frequencies between 1 and 1000 kHz, and is used primarily for breast imaging.
Various probe configurations- parallel plate and planar hand-held probe are
employed to explore the possibility of using electrical impedance imaging as an
aid for detecting breast cancer in its earliest stages. New 2-D and 3-D planar reconstruction
algorithms allow a researcher or technician to view the inside of a breast in
real time or as still images.
We hope that this technology will one day act as an adjunct to or possibly a replacement for traditional X-ray mammography. With the advantages of an impedance imaging system over traditional X-ray mammography (low cost, little or no patient discomfort, no known patient risk and no known side effects), this technology could become a welcome addition to the tools available for the fight against breast cancer.
©Rensselaer Polytechnic Institute, Created by Alexander S. Ross