Electrical impedance scanning: a new imaging technique for evaluating microcalcification in the breast?
© BioMed Central 2002
Published: 1 July 2002
Electrical impedance scanning (EIS) is a new imaging modality that utilises the different dielectric properties of malignant and benign cells. The aim of the study was to evaluate the efficacy of EIS in the evaluation of clinically occult microcalcification in the breast.
Women with areas of clinically occult microcalcification detected on X-ray mammography underwent EIS of the breast. A targeted high-resolution mode was used to assess the area of microcalcification. A bright white spot over the area of microcalcification was interpreted as a positive result. The EIS data were also analysed by post-processing, evaluating peak and average capacitance and conductivity over the region of interest compared to a normal control area in the same breast.
Thirty-five women were recruited (mean age 57, range 42–74 years). Histological diagnosis (n = 29) revealed: invasive disease (n = 1), invasive + ductal carcinoma in situ (DCIS; n = 4), DCIS (n = 4) and benign (n = 20). The remaining patients (n = 6) had radiologically benign microcalcification requiring no formal histological assessment. For the detection of malignancy using EIS imaging alone the sensitivity, specificity, positive and negative predictive values were 44.4%, 53.8%, 25.0% and 73.7%, respectively. Post-processing analysis improved the overall accuracy, with corresponding values of 55.6%, 88.5%, 62.5% and 85.2%. The difference in mean conductivity between malignant and benign lesions in the white spot region of interest was significant (P = 0.034).
EIS is able to differentiate malignant from benign disease associated with clinically occult microcalcification.