MR Fingerprinting Using the Quick Echo Splitting NMR Imaging Technique

Purpose: The purpose of the study is to develop a quantitative method for the relaxation properties with a reduced radio frequency (RF) power deposition by combining magnetic resonance fingerprinting (MRF) technique with quick echo splitting NMR imaging technique (QUEST). Methods: A QUEST-based MRF sequence was implemented to acquire high-order echoes by increasing the gaps between RF pulses. Bloch simulations were used to calculate a dictionary containing the range of physically plausible signal evolutions using a range of T-1 and T-2 values based on the pulse sequence. MRF-QUEST was evaluated by comparing to the results of spin-echo methods. The specific absorption rate (SAR) of MRF-QUEST was compared with the clinically available methods. Results: MRF-QUEST quantifies the relaxation properties with good accuracy at the estimated head SAR of 0.03 W/kg. T-1 and T-2 values estimated by MRF-QUEST are in good agreement with the traditional methods. Conclusions: The combination of the MRF and the QUEST provides an accurate quantification of T-1 and T-2 simultaneously with reduced RF power deposition. The resulting lower SAR may provide a new acquisition strategy for MRF when RF energy deposition is problematic. (C) 2016 International Society for Magnetic Resonance in Medicine.