Magnetic resonance fingerprinting with quadratic RF phase for measurement of T 2 * simultaneously with δ f , T 1 , and T 2

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 2 * in addition to δ f , T 1 , and T 2 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 δ f , T 1 , T 2 , as well as the distribution width of intravoxel frequency dispersion, Γ . A dictionary, generated through Bloch simulation, containing possible signal evolutions within the physiological range of δ f , T 1 , T 2 , and Γ , was used to perform parameter estimation. The estimated T 2 and Γ were subsequently used to estimate T 2 * . The proposed method was evaluated in phantom experiments and healthy volunteers ( N = 5). Results The T 1 and T 2 values from the phantom by qRF‐MRF demonstrated good agreement with values obtained by traditional gold standard methods (r 2 = 0.995 and 0.997, respectively; concordance correlation coefficient = 0.978 and 0.995, respectively). The T 2 * values from the phantom demonstrated good agreement with values obtained through the multi‐echo gradient‐echo method (r 2 = 0.972, concordance correlation coefficient = 0.983). In vivo qRF‐MRF‐measured T 1 , T 2 , and T 2 * values were compared with measurements by existing methods and literature values. Conclusion The proposed qRF‐MRF method demonstrated the potential for simultaneous quantification of δ f , T 1 , T 2 , and T 2 * tissue properties.