[In vivo measurements of electrical bio-impedance of breast tumors].

The electrical bio-impedance of 17 breast tumors including 12 breast cancers and 5 fibroadenomas, were measured in vivo with three-electrode method in the frequency range of 0 to 200 KHZ. The three-electrode consists of a coaxial needle electrode inserted into the tumor and a large reference electrode on upper abdominal wall. The tissue can be regarded electrically as a equivalent consisted of extracellular resistance (R1), intracellular resistance (R2), and electric capacitance of the cell membrane (C). These three parameters were calculated from the measured values of electrical bioimpedance. It was found that R1, and R2 of breast cancers were significantly higher than those of fibroadenomas (p less than 0.001), and that C of breast cancers was significantly lower than that of fibroadenomas (p less than 0.001). The measurement of the electrical impedance of breast tumor in vivo may be useful for the differential diagnosis of breast lesions.