摘要 |
A local radio frequency (RF) transmitting coil (26) of a magnetic resonance imaging system (5) has a plurality of coil elements (100). Each coil element (100) has an adjustable load (62) which is adjusted by a control unit (60) to adjust a transmitted B1 field distribution. The load can be adjusted to shim for a uniform B1 field distribution. Non-uniform B1 field distributions can be selected to perform magnetic resonance sequences that use such B1 field distributions, such as parallel imaging. The B1 field distribution can be changed during the magnetic resonance sequence to track a moving region of interest, time division multiplex parallel imaging, and the like. |