Magnetic resonance fingerprinting with quadratic RF phase for measurement of T simultaneously with δ , T , and T.

PURPOSE

This study explores the possibility of using a gradient moment balanced sequence with a quadratically varied RF excitation phase in the magnetic resonance fingerprinting (MRF) framework to quantify T in addition to , T , and T tissue properties.

METHODS

The proposed quadratic RF phase-based MRF method (qRF-MRF) combined a varied RF excitation phase with the existing balanced SSFP (bSSFP)-based MRF method to generate signals that were uniquely sensitive to , T , T , as well as the distribution width of intravoxel frequency dispersion, . A dictionary, generated through Bloch simulation, containing possible signal evolutions within the physiological range of , T , T , and , was used to perform parameter estimation. The estimated T and were subsequently used to estimate T . The proposed method was evaluated in phantom experiments and healthy volunteers (N = 5).

RESULTS

The T and T values from the phantom by qRF-MRF demonstrated good agreement with values obtained by traditional gold standard methods (r = 0.995 and 0.997, respectively; concordance correlation coefficient = 0.978 and 0.995, respectively). The T values from the phantom demonstrated good agreement with values obtained through the multi-echo gradient-echo method (r = 0.972, concordance correlation coefficient = 0.983). In vivo qRF-MRF-measured T , T , and T values were compared with measurements by existing methods and literature values.

CONCLUSION

The proposed qRF-MRF method demonstrated the potential for simultaneous quantification of , T , T , and T tissue properties.