Magnetic resonance imaging systems

Abstract

Novel apparatus and methods for magnetic resonance imaging are disclosed which improve imaging speed and resolution as well as increase efficiency, particularly in superconducting systems. In one aspect of the invention, it has been discovered that the eddy currents and harmonics which normally interfere with MRI operations can be suppressed by the construction of an active shield about the gradient-forming components of the system. The active shield, for example, can be implemented by another set of coils, placed between the gradient coils and the cryostat in a superconducting MRI system to zero particular harmonics and prevent eddy currents in the cryostat shells. By employing a set of active secondary coils the problems associated with eddy currents induced by the gradient producing coils are substantially controlled.

Dependencies are inferred from the claim text.