Magnetic resonance imaging at high magnetic fields

Magnetic Resonance imaging (MRI) has made significant advances since its introduction over fifteen years ago. The technology has been driven by a combination of higher magnetic fields, more efficient pulse sequence design and technical advances in transducer technology associated with the capture of weak magnetic resonance signals. This paper explores those advances with particular emphasis on state of the art high field MRI systems and the latest radio frequency (RF) transducers or RF coils as they are commonly referred to. The design and construction of large bore (human body sized) magnets operating at high magnetic fields (3 Tesla and above) has been the special purview of a limited number of engineering companies while the design and construction of RF coils has been addressed by a wider range of physicists and engineers working at major universities as well as those engineers working within industry. Our work at the University of Florida has been mainly focused on developing these RF coils to address the unique problems presented by operating at high magnetic fields and frequencies.