Improved Reconstruction Speed for 5D Free Running Motion Resolved Using a Variable Projection Augmented Lagrangian (VPAL) Method

Motivation: 5D free-running whole heart CMR offers CT-quality images but requires hours-long reconstruction time, preventing clinical usage. Therefore, a more efficient reconstruction algorithm is needed. Goal(s): We propose to use the advanced numerical algorithm to reduce the reconstruction time while preserving image quality. Approach: A variable projection augmented Lagrangian (VPAL) method for 5D motion-resolved image reconstruction was developed and compared with the state-of-the-art alternating direction method of multipliers (ADMM) on 15 5D free-running raw data sets. Results: When compared to the ADMM method, VPAL reduced the reconstruction time by 60%, preserved image similarity, had equivalent ejection fraction measurements, and had superior radiologist ratings. Impact: This study shows that using an advanced numerical algorithm for highly under-sampled MR reconstruction both reduces computational time and results in better image quality for diagnostics, bringing 5D free-running imaging closer to clinical usage.