Image-Guided Radio-Frequency Gain Calibration for High-Field MRI

Elodie Breton¹, KellyAnne McGorty¹, Graham C. Wiggins¹, Leon Axel¹, Daniel Kim¹

The purpose of this study was to develop a rapid, image-guided RF transmitter gain calibration procedure for high-field MRI and evaluate its performance through phantom and in vivo experiments at 3T and 7T. Using a single-shot TurboFLASH pulse sequence, a series of saturation-no-recovery images was acquired by varying the flip angle of the preconditioning pulse. In the resulting images, the signal null occurs in regions where the flip angle of the preconditioning pulse is 90, and the mean signal within a region-of-interest can be plotted as a function of the nominal flip angle to quantitatively calibrate the RF transmitter gain.