Retrospective motion correction through multi‐average k‐space data elimination (REMAKE) for free‐breathing cardiac cine imaging. Issue 6 (10th February 2023)

• Record Type: Journal Article
• Authors: Neofytou, Alexander Paul; Neji, Radhouene; Kowalik, Grzegorz Tomasz; Mooiweer, Ronald; Wong, James; Fotaki, Anastasia; Ferreira, Joana; Evans, Carl; Bosio, Filippo; Mughal, Nabila; Razavi, Reza; Pushparajah, Kuberan; Roujol, Sébastien
• Is Part Of: Magnetic resonance in medicine. Volume 89:Issue 6(2023)
• Page Start: 2242
• Page End: 2254
• Publication Date: 2023-02-10
• Subjects: 2D cine -- cardiac MRI -- free‐breathing -- retrospective respiratory motion correction; Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.29613
• Languages: English
• ISSNs: 0740-3194

Abstract

Abstract : Purpose: To develop a motion‐robust reconstruction technique for free‐breathing cine imaging with multiple averages. Method: Retrospective motion correction through multiple average k‐space data elimination (REMAKE) was developed using iterative removal of k‐space segments (from individual k‐space samples) that contribute most to motion corruption while combining any remaining segments across multiple signal averages. A variant of REMAKE, termed REMAKE+, was developed to address any losses in SNR due to k‐space information removal. With REMAKE+, multiple reconstructions using different initial conditions were performed, co‐registered, and averaged. Both techniques were validated against clinical "standard" signal averaging reconstruction in a static phantom (with simulated motion) and 15 patients undergoing free‐breathing cine imaging with multiple averages. Quantitative analysis of myocardial sharpness, blood/myocardial SNR, myocardial‐blood contrast‐to‐noise ratio (CNR), as well as subjective assessment of image quality and rate of diagnostic quality images were performed. Results: In phantom, motion artifacts using "standard" (RMS error [RMSE]: 2.2 ± 0.5) were substantially reduced using REMAKE/REMAKE+ (RMSE: 1.5 ± 0.4/1.0 ± 0.4, p < 0.01). In patients, REMAKE/REMAKE+ led to higher myocardial sharpness (0.79 ± 0.09/0.79 ± 0.1 vs. 0.74 ± 0.12 for "standard", p = 0.004/0.04), higher image quality (1.8 ± 0.2/1.9 ± 0.2 vs. 1.6 ± 0.4 for "standard", p = 0.02/0.008), and a higher rate of diagnostic quality images (99%/100% vs. 94% for "standard"). Blood/myocardial SNR for "standard" (94 ± 30/33 ± 10) was higher vs. REMAKE (80 ± 25/28 ± 8, p = 0.002/0.005) and tended to be lower vs. REMAKE+ (105 ± 33/36 ± 12, p = 0.02/0.06). Myocardial‐blood CNR for "standard" (61 ± 22) was higher vs. REMAKE (53 ± 19, p = 0.003) and lower vs. REMAKE+ (69 ± 24, p = 0.007). Conclusions: Compared to "standard" signal averaging reconstruction, REMAKE and REMAKE+ provide improved myocardial sharpness, image quality, and rate of diagnostic quality images.