Magnitude image PSNRs plotted vs. total acceleration R for representative slices of (a–b) two T1-weighted MPRAGE datasets and (c) the T2-weighted TSE dataset for GRAPPA, GRAPPA with multichannel adaptive local Wiener filter-based denoising, L1 SPIR-iT, and DESIGN denoising. The inset regions display the PSNR trends for smaller R, where the methods’ performances are more similar. Note that L1 SPIR-iT is limited here by uniform undersampling. For a given acceleration, the tuning parameter is determined for each dataset individually.