Efficient MRF at 0.55T with long readouts and concomitant field effects correction

We demonstrate FISP-MRF at 0.55T with improved efficiency using longer spiral readouts and concomitant field effect correction. 2D axial FISP-MRF is performed with 3 different readout durations and at 2 different off-isocenter locations, reconstructed without and with MaxGIRF concomitant field correction. Spatial blurring induced by concomitant field effect was successfully mitigated. In-vivo MRF white matter T2 achieved tighter distribution with longer readouts, e.g., the coefficient of variation decreased from 9.9% to 4.9%.