Differentiation of mammographically suspicious lesions: evaluation of breast ultrasound, MRI mammography and electrical impedance scanning as adjunctive technologies in breast cancer detection.

AIM: Various modalities are used as an adjunct to mammography for differentiation of potentially suspicious breast lesions. Electrical impedance scanning (EIS) is a new technique based upon the principle that cancer cells exhibit altered local dielectric properties and thus show measurably higher conductivity values. The accuracy of differentiation of benign and malignant breast lesions was evaluated to determine whether EIS duplicates or supplements the results obtainable from ultrasound (US) or magnetic resonance imaging (MRI).
MATERIALS AND METHODS: One hundred mammographically suspicious lesions were examined using US, MRI and EIS. Definitive histology was acquired through either lesion biopsy or surgical excision.
RESULTS: Fifty of 62 malignant lesions were correctly identified using EIS (81% overall sensitivity), 24/38 benign lesions were correctly identified as benign (63% specificity). Negative predictive value and positive predictive value of 67 and 78% were observed, respectively. kappa-factor evaluation revealed a value of 0.82 between MRI and EIS and 0.62 between US and EIS.
CONCLUSIONS: EIS may be a valuable adjunct for differentiation of suspicious mammographic lesions. Based upon the calculated kappa-factor, EIS results supplement US examinations. Artifacts (superficial skin lesions, poor contact, air bubbles) currently result in the high false-positive rate of EIS.