Rapid simultaneous b0 and b1 mapping for magnetic resonance imaging

A magnetic resonance imaging (MRI) system comprising:

• a resonance assembly comprising a plurality of gradient coils configured to produce magnetic field gradients for spatially encoding MR signals;
• a controller configured to control the resonance assembly to:
• generate at least one first pre-saturation RF pulse having a first flip angle;
• following each first pre-saturation RF pulse, generate a slice selective gradient and corresponding first plurality of radiofrequency (RF) excitation pulses to excite nuclear spins in a slice in a subject, whereby each time between two consecutive RF excitation pulses in the first plurality of RF excitation pulses defines a first gradient-echo time interval;
• generate first readout gradient and a second readout gradient in each first gradient-echo time interval, wherein the first readout gradient and the second readout gradient comprise a first gradient echo sequence;
• determine a B0 for each first gradient-echo time interval based on the first readout gradient and the second readout gradient;
• generate at least one second pre-saturation RF pulse having a second flip angle, wherein the second flip angle is different than the first flip angle;
• following each second pre-saturation RF pulse, generate the slice selective gradient and corresponding second plurality of radiofrequency (RF) excitation pulses to excite nuclear spins in the slice in the subject, whereby a time between two consecutive RF excitation pulses in the second plurality of RF excitation pulses defines a second gradient-echo time interval;
• generate at least one of the first readout gradient and the second readout gradient in each second gradient-echo time interval, wherein the at least one of the first readout gradient and the second readout gradient comprise a second gradient echo sequence;
• wherein each of the second gradient-echo time intervals is paired with a respective one of the first gradient-echo time intervals, each pair of first and second gradient-echo time intervals corresponding to the slice;
• and
• determine a B1 for each pair of first and second gradient-echo time intervals based on the first gradient echo sequence and the second gradient echo sequence.