Breast imager seen as adjunct to mammo

April 25, 2001

A device that measures low-level electrical current shows promise as an adjunct to screening mammography. Electrical impedance scanning, when done after mammography, may be more sensitive than ultrasound, according to research published in the April

A device that measures low-level electrical current shows promise as an adjunct to screening mammography. Electrical impedance scanning, when done after mammography, may be more sensitive than ultrasound, according to research published in the April issue of Clinical Radiology. The technique fails to match the sensitivity of breast MRI, however. Results of the comparative study suggest that EIS and ultrasound together could provide a viable alternative when MRI is contraindicated.

EIS relies on differences in conductivity between normal and cancerous tissue, indicated by the speed at which electricity travels through breast tissue. Low-impedance cancers (good conductors) show up on display monitors as bright white spots; normal tissue with higher impedance registers as gray. Because benign lesions have electrical properties noticeably different from malignancies, EIS can help rule out cancer in patients with mammographically suspect lesions, according to the authors. Reports of the technique’s sensitivity have varied significantly between institutions, however, and EIS has also been criticized for its low specificity.