Superconducting magnets for magnetic resonance imaging applications

Recent applications of one-meter bore Superconducting magnets to allow imaging of human brain tissue, the central nervous system, the spine and other internal organs by utilizing the phenomenon of nuclear magnetic resonance (NMR) have resulted in a revolutionary development in medical diagnostics and a unique application of superconductive technology in medicine. At present, S/C magnets are most frequently utilized in MRI systems because they can most effectively produce the highly uniform, stable, and powerful field required for the imaging process. Although it has been demonstrated that quite acceptable image quality can be obtained at virtually any magnetic field strength, from 0.3 Tesla through 2.0 Tesla, the question of optimum central field for MR Imaging and Spectroscopy is still open. Since S/C magnets offer the widest range of field strengths, they are helping to contribute to the collection of clinical data which will eventually clarify the question of optimum central field for Magnetic Resonance diagnostic applications. In addition, S/C magnets have contributed to the successful application of MRI in mobile, or truck-based systems, with operating data on S/C magnets showing high magnet system availability in actual clinical mobile use. This data will be reviewed as will the design considerations of the S/C MRI magnet cryostat and cryogen recondensers, particularly as they relate to reliability, uptime, and system level interactions with the imaging hardware and software.