Apparatus for determining the electrical conductivity of target cervical tissue using magnetic impedance spectroscopy comprising: an excitation coil for producing a magnetic field which is capable of inducing currents in the target cervical tissue a gradiometer for detecting perturbations in said magnetic field caused by said induced currents the gradiometer including screening means for minimising sensitivity to tissues other than the target tissue processing means for determining an electrical conductivity of said target cervical tissue from said perturbations.
