A pad which has a magnetic permeability greater than that of free space at the
frequency of nuclear magnetic resonance but which is non-magnetic in steady magnetic
fields is disposed between an RF coil and the surface of a patient. The pad is
surmounted by a block having similar properties. Two further pads extend from the
ends of the block to the surface of the patient. The pads and block guide magnetic
flux, which is indicative of magnetic resonant active nuclei in the patient, towards
an RF coil which is spaced apart from the surface of the patient/object under examination.
