ABSTRACT
Some great challenges still attend MRI, if it is to meet the expectations of the growing numbers of potential applications. Functional and molecular imaging, for example, require that MRI be capable of ever more highly temporally and spatially resolved images, with high contrast between different tissues, high sensitivity, and high SNR. This has driven a trend in the direction of very high field superconductive magnets (7 T or greater) to improve sensitivity and, consequently, temporal resolution. At the same time, the magnetic field has to be better shimmed to also improve spatial resolution while avoiding distortions, fundamental if MRI has to be used as a precise localizing technique. Similar demands and responses are to be seen in real-time imaging.
