Abstract: Apparatus for measuring the electrical conductivity of a subject comprises a coil for producing a substantially uniform magnetic field within a predetermined volume and a transport assembly for causing relative movement between the subject and the predetermined volume so as to move at least portions of the subject into and out of the volume. A measuring circuit is coupled with the coil for measuring the electrical conductivity thereacross and a control circuit causes the measuring circuit to measure the electrical conductivity across the coil a plurality of times during movement of the subject relative to the volume so as to obtain a plurality of measurements of the electrical conductivity across the coil with different portions of the subject within the volume.