Simple Method for Bloch-Siegert B1 Map Data Processing

A simple data processing method for calculating B1 map data using the Bloch-Siegert shift method is described. The proposed method uses a phase conjugate approach instead of conventional phase subtraction. The proposed method has the dual advantages of 1) not requiring phase unwrapping and 2) enabling simple and SNR-efficient complex data combination for multi-channel phased array coils. One consequence of using a phase conjugate approach is a reduced range of resolvable B1 due to phase aliasing. A practical solution is offered to resolve this problem by making an assumption of the realistic range of expected B1.