Electrical impedance imaging of the breast (TranScan TS 2000): initial UK experience
© Current Science Ltd 2000
Published: 1 October 2000
The TranScan TS 2000 (Siemens Medical Systems) is a real-time non-invasive radiation-free imaging device for breast examination, which utilises the inherent differences in electrical impedance between neoplastic and normal tissue.
Tissue changes associated with cancer cause significant variations in dielectric properties. These result in cytological and histological changes involving intra- and extracellular water, membrane properties and packing density associated with malignant transformation. Electrical impedance (both conductivity and capacitance) is typically 20-40 times lower than normal tissue. Therefore, when a small alternating current is applied across the breast, malignant tissue distorts the electric field generated and this can be detected and displayed.
Since February 2000 we have been evaluating the TranScan TS 2000 in our unit, both for symptomatic patients and women with screen-detected abnormalities. We have retrospectively analysed patients undergoing both mammographic and TranScan examinations who subsequently underwent excision or core biopsy. Initial data suggests the TranScan is a useful addition to the assessment of patients, increasing diagnostic accuracy in terms of both sensitivity and specificity. Further large-scale studies are needed to demonstrate whether a substantial reduction in biopsies of benign lesions and/or an increase in number of cancers detected will result from the use of the TranScan.