Figure 1

Schematic of the combined B0- and B1-map sequence. The multi-slice acquisition is cardiac triggered, the magnetization is reset with an 8 ms 90° BIR-4 pulse, relaxed during T_SR, and acquired with spiral readouts after a frequency selective fat saturation pulse. Each acquisition box in the figure denotes slice (S1-Sn), excitation angle (0°, α, or 2α), and TE (TE1 or TE2). The two shown cardiac cycles will be repeated according to how many spiral interleaves are acquired. This leads to four images per slice with all combinations of flip angles α and 2α, and echo time TE1 and TE2. α-TE1 amd α-TE2 are used to calculate the B1-map [5], whereas α-TE1 and α-TE2 are used to calculate the B0-map [1]. To reduce the deposited RD power, the flip angle of the 2α-TE2 acquisition was set to zero as this image is not used.