PASSIVE SHIMS TO INCREASE THE EFFECTIVE B0 AND B1 UNIFORMITY IN A BODY COIL

摘要

A magnetic resonance imaging system (10) includes a local coil (40) for receiving a resonance signal induced by a whole body quadrature coil (32). The local coil (40) includes a dielectric former (68) in which a plurality of receive coils (60, 74, 76, 78) and a passive B0 and B1 field shim (62, 82) are mounted. The passive shim includes a plurality of capacitively coupled elements (64) of an electrically conductive diamagnetic, paramagnetic, ferromagnetic material which passively shield and enhance the field in local regions. A surface configuration of the elements is tailored to optimize local B1 homogeneity and a mass of the elements is configured to optimize local B0 field homogeneity.