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 different iation of potentially suspicious breast lesions. Electrical impedance scann ing (EIS) is a new technique based upon the principle that cancer cells exh ibit altered local dielectric properties and thus show measurably higher co nductivity values. The accuracy of differentiation of benign and malignant breast lesions was evaluated to determine whether EIS duplicates or supplem ents the results obtainable from ultrasound (US) or magnetic resonance imag ing (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 a s benign (63% specificity). Negative predictive value and positive predicti ve value of 67 and 78% were observed, respectively. kappa -factor evaluatio n 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 suspiciou s mammographic lesions. Based upon the calculated kappa -factor, EIS result s supplement US examinations. Artifacts (superficial skin lesions, poor con tact, air bubbles) currently result in the high false-positive rate of EIS, (C) 2001 The Royal College of Radiologists.