Figure 2

3D though-time spiral GRAPPA reconstruction flow diagram. Fully-sampled free-breathing data is used to calibrate the spiral GRAPPA kernels. For each cardiac phase, the skipped arms of the undersampled dynamic data (dashed gray curves) within each partition encoding step were reconstructed with the spiral GRAPPA weights. After NUFFT of the reconstructed dynamic data, the Cartesian coil images were combined with an adaptive algorithm to yield each volumetric timeframe.