This study applied a fast acquisition scheme for a fully quantitative 3D magnetic resonance fingerprinting scan with a total acceleration factor of 144 as compared with the Nyquist rate, such that 3D T , T , and proton density maps can be acquired with whole-brain coverage at clinical resolution in less than 5 min. Magn Reson Med 79:2190-2197, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Magnetic Resonance Fingerprinting (MRF) is a new approach to quantitative magnetic resonance imaging that allows simultaneous measurement of multiple tissue properties in a single, time-efficient acquisition. The ability to reproducibly and quantitatively measure tissue properties could enable more objective tissue diagnosis, comparisons of scans acquired at different locations and time points, longitudinal follow-up of individual patients and development of imaging biomarkers. This review provides a general overview of MRF technology, current preclinical and clinical applications and potential future directions. MRF has been initially evaluated in brain, prostate, liver, cardiac, musculoskeletal imaging, and measurement of perfusion and microvascular properties through MR vascular fingerprinting.

MORF improves the insensitivity of MRF toward rigid-body motion occurring during any part of the MRF acquisition.

Multiparametric quantitative imaging is gaining increasing interest due to its widespread advantages in clinical applications. Magnetic resonance fingerprinting is a recently introduced approach of fast multiparametric quantitative imaging. In this article, magnetic resonance fingerprinting acquisition, dictionary generation, reconstruction, and validation are reviewed. K E Y W O R D Sdictionary, MR fingerprinting, multiparametric mapping, pattern recognition, quantitative imaging, relaxation timeIn the proof-of-principle implementation of MRF by Ma et al, 16 an inversion recovery-prepared balanced SSFP (bSSFP) based approach (Figure 2) was used, as the bSSFP sequence has been extensively studied. [23][24][25][26][27][28][29][30][31] The properties of retaining spin history, high SNR, high scan efficiency, and high sensitivity to T 1 , T 2 , and off-resonance frequencies make F I G U R E 1 Overview of the magnetic resonance fingerprinting (MRF) framework. Data are acquired such that different tissues have unique fingerprints. The dictionary contains a discretized subset of all anticipated tissue signals generated through simulations. The acquired fingerprints are compared with the simulated fingerprints from the dictionary (pattern recognition) to identify the underlying tissue in each voxel. From the identified dictionary entry, tissue properties are assigned to each voxel to generate the property maps Property maps F I G U R E 5 Example of in vivo comparison of the bSSFP-MRF and FISP-MRF of one asymptomatic volunteer acquired at 3 T. In this subject the shimming was intentionally corrupted to obtain severe B 0 inhomogeneity. In this situation, the bSSFP-MRF presents banding artifacts, while the FISP-MRF approach maintains a diagnostic image quality (a detailed version of this figure is available online)