| In January 2006, an Electrical
Impedance Tomography (EIT) system developed at NSF’s Bernard M. Gordon
Center for Subsurface Sensing and Imaging Systems, an Engineering Research
Center based at Northeastern University, went into clinical trials at the
Massachusetts General Hospital (MGH). The Center’s EIT program is
on the cutting edge of impedance imaging of breast tissue.
Mammography, currently the
best-available method of detecting breast cancer, has a significant error
rate, which can result in unnecessary biopsies and patient stress.
Also, the risk posed by x-ray exposure during mammography is too high to
warrant routine use for women under the age of 40.
The Center’s EIT system doesn’t
use x-rays, so there’s no exposure risk. It may also prove to be more accurate
than traditional mammography. EIT systems work by applying electrical
currents through electrodes on the surface of the breast and recording
the voltages that result on those electrodes. The Center's EIT system
operates and displays data in real time.
Successful trials of the
EIT system could result in a reduction in the number of unnecessary biopsies
for breast cancer and a decrease in the number of missed cancers in mammography
screening. A broader impact may be the reduction in breast cancer
morbidity and mortality and a reduction in the societal cost of breast
cancer care.
In 2007, Center researchers
at Rensselaer Polytechnic Institute (RPI) and MGH achieved promising early
clinical results from the new imaging system. RPI Professors David Isaacson,
Jonathan Newell, and Gary Saulnier, in collaboration with Dr. Daniel Kopans
and the MGH tomosynthesis group, reconstructed the electrical impedance
spectra (EIS) in 3-D for 11 normal breasts, 1 benign fibroadenoma, and
3 breasts with cancer (see figure). The team has identified a parameter
derived from the reconstructed EIS data that can clearly distinguish malignant
from normal or benign tissue, as well as approximately localize the cancers
in this small group of clinical patients. |
