Motion Corrected Subspace Reconstruction With Navigators for Quantitative High-Resolution Spiral First-Pass Myocardial Perfusion Imaging at 3 Tesla

Purpose: To optimize a spiral acquisition using a fixed-angle subspace navigator and golden angle trajectory, combined with motion-corrected (MOCO) subspace reconstruction, for motion-robust, quantitative high-resolution whole-heart first-pass perfusion imaging at 3 T. Methods: Spiral acquisition used a fixed-angle navigator to extract the temporal basis, combined with seven spiral arms ((1 + 7)-arm) rotated using k–t golden angles, yielding a 90 ms temporal footprint for two interleaved slices at 1.3 × 1.3 mm². Non-rigid deformation fields estimated from auxiliary images were incorporated into the subspace reconstruction. Performance was tested in XCAT simulations and 5 retrospectively undersampled free-breathing datasets. Prospective reconstructions using Subspace, L1-SENSE, and SENSE with and without MOCO from 22 patients were visually graded (1–5) by three cardiovascular imagers. In 11 of these patients an arterial input function (AIF) was acquired and myocardial blood flow (MBF) maps were calculated using Fermi-function deconvolution. Results: In simulations and retrospective datasets, the navigator captured cardiac motion and contrast dynamics effectively, and the (1 + 7)-arm k–t GA DD1-Hs configuration improved subspace reconstruction through increased spatiotemporal incoherency. In prospective studies, Subspace-MOCO achieved the highest visual scores (p < 0.001), with MOCO improving all methods (EMM ± 1.96 × SE: SENSE-MOCO 2.2 ± 0.2, L1-SENSE-MOCO 4.1 ± 0.2, Subspace-MOCO 4.6 ± 0.12). Subspace-MOCO also provided superior boundary sharpness and global edge sharpness, higher NCC and NMI (p < 0.05). Its MBF values were similar to those obtained with SENSE-MOCO and closer than those reconstructed from L1-SENSE-MOCO. Conclusions: The proposed navigator-guided MOCO subspace reconstruction substantially reduces respiratory motion artifacts and enables high-resolution, motion-corrected whole-heart quantitative spiral perfusion imaging.