Electrical impedance scanning for classifying suspicious breast lesions: first results

Abstract

It has long been established that cancer cells exhibit altered local dielectric properties compared with normal cells. Consequently, different electrical conductivity and capacitance are measurable in malignant vs normal tissues. In this study we evaluated the reliability of electrical impedance scanning (EIS), a new technology, for the classification of suspicious lesions: differentiating benign from malignant, and as a primary means of detection of breast cancer. Fifty-two women with 58 sonographically and/or mammographically suspicious findings were examined using electrical impedance scanning. Two different examination modes of TransScan TS2000 (Siemens, Erlangen, Germany), the standard-resolution mode for a routine overview examination, and the targeted high-resolution mode for a local examination of the suspicious lesion were used. All patients were additionally imaged by MR mammography (MRM) and underwent core-biopsy and/or surgical treatment after the EIS examination. With respect to the histopathological findings (29 malignant and 29 benign lesions) 27 of 29 (93.1%) malignant lesions were correctly identified using the high-resolution mode of EIS, whereas 19 of 29 (65.5%) benign lesions were correctly identified as benign (10 of 29 benign lesions showed as false-positive findings). Negative and positive predictive values of 90.5 and 73.0% were observed, respectively. Using the standard-resolution mode 22 of 29 malignancies were correctly detected (sensitivity 75.9%), whereas 22 of 29 were correctly identified as benign (specificity 72.4%). Electrical impedance scanning appears to be a promising new technology providing a relatively high sensitivity for the verification of suspicious mammographic and/or sonographic lesions especially using the high-resolution mode for local examinations. Artifacts, such as signals from superficial skin lesions, poor contact, and air bubbles, are currently a limitation.

Electrical Impedance Tomography of Breast Cancer

“…Therefore, the method is adequately sensitive to conductivity changes in malignant tissues. In previous studies they had reported 20-40 fold conductivity changes in benign versus malignant tissues in humans [2,3,4].…”

“…Radial. 10: 1555-1561(2000]. Therefore, in-vivo impedance imaging of suspicious lesions could aid in diagnosis of malignant tumors.…”

“…Radial. 10: 1555-1561(2000]. The goal of this study was to acquire in-vivo impedance images from live animals with tumors to assess the diagnostic potential of MR-EIT.…”

Electrical Impedance Tomography of Breast Cancer

“…A linear set of equations giving the relation between conductivity perturbations and magnetic flux density measurements around initial values is obtained: Ab = SAa (11) where Ab = b -bini is the change in magnetic flux density with respect to initial, S is the sensitivity matrix, and Aca = G -C'ini. S is calculated for known geometry, boundary conditions, and initial conductivity and given the measurements, Ab, conductivity is calculated.…”

“…Electrical Impedance Scanning (EIS) is a new technique recently introduced to aid in the diagnosis of malignant breast tumors (10)(11)(12)(13)(14). The device that uses this technique generates a map of the conductivity distribution inside the breast tissue.…”