Impedance systems and methods of use. The impedance systems include only one electrode positioned upon an elongate body, and at least two external electrodes. The only one electrode is configured to both excite an electric field and detect the electric field. The only one electrode works with a first external electrode to generate an electric field and works with a second external electrode to obtain conductance measurements from the electric field. In other embodiments the first external electrode and/or the second external electrode may also be configured to both excite an electric field and detect the electric field. In other embodiments, both the first external electrode and the second external electrode can work with the only one electrode to both generate an electric field and obtain at least one conductance measurement.