Materials mapped with NMR

Since its conception by Paul Lauterbur at the State University of New York, Stony Brook, USA, in the early 1970s, nuclear magnetic resonance imaging (NMRI) has, for many physicians and patients, become the preferred method for non-invasive medical diagnosis of many diseases. High resolution clinical images can now be generated routinely. The contrast between the different tissues in a biomedical NMR image (see figure 1) is due to a multitude of mechanisms; nuclear density itself is a rather poor clinical contrast “agent”, and by far the most effective clinical NMRI contrast mechanism is NMR relaxation, dictated by the lifetime of a particular nucleus in a given excited nuclear state.