Rapid RF Field Mapping Using a Slice-Selective Pre-Conditioning RF Pulse

Sohae Chung¹, Daniel Kim¹, Elodie Breton¹, Leon Axel¹

The B₁ field uniformity plays an important role in determining the image quality in MRI, since such an RF pulse excitation causes flip angle variations that confound quantitative results. In this study, we describe a novel and efficient method for rapid B₁ mapping using a slice-selective pre-conditioning RF pulse followed by TurboFLASH pulse sequence. This method is insensitive to off-resonance, with less than 1.4% B₁ measurement error up to 500Hz off-resonance and the total scan time is less than 2s with SR module. Therefore, this method can be used for quantitative MRI applications that require fast B₁ calibration.