Operative instrument providing enhanced visibility area in MR image

Claim 1

An operative instrument insertable in an object subjected to NMR examination for providing a localized area having improved visibility properties in an MR image of the object obtained from the examination, the examination being carried out in a magnetic field created externally of said object, said instrument comprising: an instrument body which is sufficiently small in size, relative to said object, that the instrument body can be inserted into the object so that the object surrounds the instrument; means coupled to said instrument body for supplying a paramagnetic relaxant to a localized area within said object and contiguous to said body instrument for interaction with NMR active nuclei capable of emitting an NMR signal and proximate to said relaxant, said paramagnetic relaxant having an electron spin system generating net magnetization in the external magnetic field; and means for supplying electron spin resonance energy via the instrument body for said relaxant to saturate its electron spin system, thereby to amplify, by dynamic nuclear polarization, the NMR signal obtained from the nuclei during the NMR examination so that said area will have improved visibility properties in an MR image.