Abstract: Described are embodiments for slice-selective excitation for MRI that utilize multiple RF transmit coils, each of which are driven with a separate independent current waveform. These embodiments allow slice-selective excitation with slice profile and excitation time similar to other single-channel excitation, but with reduction in SAR caused by the transverse component of the RF field by a factor up to the number of excitation coils.

Abstract: Described are embodiments for slice-selective excitation for MRI that utilize multiple RF transmit coils, each of which are driven with a separate independent current waveform. These embodiments allow slice-selective excitation with slice profile and excitation time similar to other single-channel excitation, but with reduction in SAR caused by the transverse component of the RF field by a factor up to the number of excitation coils.

Abstract: Described are embodiments for slice-selective excitation for MRI that utilize multiple RF transmit coils, each of which are driven with a separate independent current waveform. These embodiments allow slice-selective excitation with slice profile and excitation time similar to other single-channel excitation, but with reduction in SAR caused by the transverse component of the RF field by a factor up to the number of excitation coils.

Abstract: Described are embodiments for slice-selective excitation for MRI that utilize multiple RF transmit coils, each of which are driven with a separate independent current waveform. These embodiments allow slice-selective excitation with slice profile and excitation time similar to other single-channel excitation, but with reduction in SAR caused by the transverse component of the RF field by a factor up to the number of excitation coils.

Abstract: Inhomogeneity of the radio-frequency (RF) field B1 interferes with imaging methods such as fat saturation which are sensitive to variations in the tip angle achieved by an RF pulse. In addition, in the common case in which the MR signal is received through the same coil used for excitation, the RF field is a measure of the receiver coil sensitivity. If the RF field can be measured, RF pulses could be designed specifically to counteract the inhomogeneity of the RF field. Additionally, maps of the RF field could be used as coil sensitivity maps, which may be used for image intensity correction. A phase-sensitive method of B1 mapping is presented which is applicable over a wide range of RF inhomogeneity corresponding to flip angles ranging from about 45 to 135 degrees. This method requires two or three acquisitions in addition to the acquisition of a main-field (B0) field map.