The Past, Present and Future of MRI Superconducting Magnet Development

Abstract

MR magnets have quickly moved from applications in laboratory spectroscopy instruments to application in magnetic resonance imaging (MRI) in hospitals. The level of effort in universities and medical instrument companies directed at MRI and spectroscopy for diagnostics is substantial, and as a result, the magnet performance requirements are changing with time. Generally, these changing requirements are in the field strength, the field quality, and the interaction of the magnet with other system components. The application in hospitals, where cryogenics and magnets are not otherwise in use, brings its own set of demands to magnet design and performance. It is desirable to minimize the support necessary for cryogens by means of active coolers or liquefiers. Mobile MRI systems are also being used that impose their own set of demands on the magnet and cryogenic subsystem. Magnetic shielding that facilitates installation in the vicinity of other medical equipment is necessary in many installations.

Future developments will depend on the success of current research. Proposals have been made for MR systems that will require as much as 10 T in a 1 m bore for research. The applications that will prove to be successful in a clinical environment will ultimately depend on the cost and effectiveness of the procedure. The magnet, which is a major element in terms of both cost and performance, will play an important role.