NMR imaging - Non-medical applications

Nuclear Magnetic Resonance Imaging (NMRI ) has become a diagnostic technique of prime importance in clinical medicine, with a steady increase in applications due in large part to advances in image quality and the speed with which they can be obtained. The universality of the magnetic resonance phenomenon is well known to chemists and physicists. By associating other types of information with images, new applications have been developed, such as magnetic resonance angiography, local spectroscopy and spectroscopic imaging, as well as MRI of brain function based on the observation of changes in cerebral blood circulation.

The growth of non-medical NMRI applications seems to be lagging behind that of medical NMRI. This lag is due to the technical difficulties involved in designing specific equipment, the vast range of applications and the specific nature of each one (which complicates standardization of equipment), and the high cost of this equipment. Its slow growth is also due to the particular nature of NMRI, which involves imposing a spatial localization on a chemically and physically sensitive spectroscopic technique. In chemical analysis, the fields of imaging and spectroscopy are not closely linked, except perhaps for surface analysis. NMRI, on the other hand, provides both an imaging technique and a local probe of spectroscopic properties within a sample.

The aim of this chapter is not to review the physical principles of NMRI, nor to present an overview of technical developments in non-medical applications, as these topics have already been presented in other articles. The aim here is to assess the current status and future direction of this technique, and to highlight the variety of information contained in NMR images, through recent applications.