Retrospective motion correction for cardiac multi-parametric mapping with dictionary matching-based image synthesis and a low-rank constraint

Purpose: To develop a model-based motion correction (MoCo) method that does not need an analytical signal model to improve the quality of cardiac multi-parametric mapping. Methods: The proposed method constructs a hybrid loss that includes a dictionary-matching loss and a signal low-rankness loss, where the former registers the multi-contrast original images to a set of motion-free synthetic images and the latter forces the deformed images to be spatiotemporally coherent. We compared the proposed method with non-MoCo, a pairwise registration method (Pairwise-MI), and a groupwise registration method (pTVreg) via a free-breathing Multimapping dataset of 15 healthy subjects, both quantitatively and qualitatively. Results: The proposed method achieved the lowest contour tracking errors (epicardium: 2.00 +/- 0.39 mm vs 4.93 +/- 2.29 mm, 3.50 +/- 1.26 mm, and 2.61 +/- 1.00 mm, and endocardium: 1.84 +/- 0.34 mm vs 4.93 +/- 2.40 mm, 3.43 +/- 1.27 mm, and 2.55 +/- 1.09 mm for the proposed method, non-MoCo, Pairwise-MI, and pTVreg, respectively; all p < 0.01) and the lowest dictionary matching errors among all methods. The proposed method also achieved the highest scores on the visual quality of mapping (T1: 4.74 +/- 0.33 +/- 0.33 vs 2.91 +/- 0.82, +/- 0.82, 3.58 +/- 0.87, +/- 0.87, and 3.97 +/- 1.05, +/- 1.05, and T2: 4.48 +/- 0.56 +/- 0.56 vs 2.59 +/- 0.81, +/- 0.81, 3.56 +/- 0.93, +/- 0.93, and 4.14 +/- 0.80 +/- 0.80 for the proposed method, non-MoCo, Pairwise-MI, and pTVreg, respectively; all p < 0.01). Finally, the proposed method had similar T1 and T2 mean values and SDs relative to the breath-hold reference in nearly all myocardial segments, whereas all other methods led to significantly different T1 and T2 measures and increases of SDs in multiple segments. Conclusion: The proposed method significantly improves the motion correction accuracy and mapping quality compared with non-MoCo and alternative image-based methods.