Methods and systems for estimating transmit attenuation for a magnetic resonance imaging scan

A magnetic resonance imaging (MM) system, comprising:

• a transmit radio frequency (RF) coil;
• an amplifier configured to drive the transmit RF coil;
• and
• a controller coupled to the transmit RF coil and the amplifier, the controller configured to:
• set a reference value of transmit attenuation for the amplifier;
• acquire a two-dimensional B1 field map with the transmit attenuation set at the reference value;
• determine a mean flip angle from the B1 field map;
• determine a transmit attenuation correction value based on a prescribed flip angle and the mean flip angle;
• correct the reference value of transmit attenuation with the transmit attenuation correction value to obtain a final value of transmit attenuation;
• and
• perform an imaging scan with the transmit attenuation set at the final value.

A non-transitory computer-readable medium comprising instructions that, when executed, cause a processor to:

• set a reference value of transmit attenuation for an amplifier of a transmit radio frequency (RF) coil of a magnetic resonance imaging (MM) device;
• operate the MRI device to acquire a two-dimensional B1 field map with the transmit attenuation set at the reference value;
• determine a mean flip angle from the B1 field map;
• determine a transmit attenuation correction value based on a prescribed flip angle and the mean flip angle;
• correct the reference value of transmit attenuation with the transmit attenuation correction value to obtain a final value of transmit attenuation;
• and
• operate the MM device to perform an imaging scan with the transmit attenuation set at the final value.