Figure 1.

Single‐run water‐fat resolving magnetic resonance fingerprinting (MRF) sequence and image processing pipeline. A, The MRF train, similar to the one used in Sommer et al,54 consists of 1000 flip angles, but each 2 consecutive ones having the same value being followed by a different TE. This sequence was constructed by interleaving 2 identical flip angle trains of length 500, each having its own constant TE. The entire train is preceded by an inversion pulse seen at shot number 0. B, The 1000 MRF frames are corrected for B ₀ inhomogeneities by applying the conjugate phase reconstruction (CPR) using the measured B ₀ map and the simulated spiral k‐space trajectory as input. Subsequently, the water signal is separated from the fat signal with a 2‐point DIXON, using a 7‐peak fat model. The resulting 500 fat MRF frames are deblurred by applying CPR at a stationary frequency of 440 Hz (chemical shift offset). Water and fat (WF) MRF frames are matched individually to the same dictionary using the measured $B_1^{+}$ map as input, resulting in a T₁, T₂, and M₀ map for water and for fat separately, which are combined into water and fat fraction (FF) maps