Fig. 2

Pipeline to reconstruct fetal multidimensional PC-CMR data. (a) PC-CMR data is acquired with continuously incremented velocity encoding (encodes are color coded as: flow compensation = red; through-plane encode = blue; orthogonal in-plane encodes = black and green) and golden angle radial sampling. (b) Temporal windows of 200 ms are created for real-time reconstruction using compressed sensing (CS) with temporal and spatial total variation sparsity constraints (TTV and STV, respectively). Motion tracking and data rejection are performed, and the retained k-space data is motion corrected (red dotted arrow). (c) Temporal windows of 25 ms are created for real-time reconstruction using CS, again with TTV and STV constraints, and metric-optimized gating is performed on the magnitude data (green dotted arrow). (d) The data are binned into n cardiac phases (CP), and CS is used to create a multidimensional fetal flow CINE, with sparsity constraints in the STV, complex difference (CD) and temporal Fourier transform (TFT) domains