Respiratory motion corrected 4D flow using golden radial phase encoding. Issue 2 (29th August 2019)

• Record Type: Journal Article
• Authors: Kolbitsch, Christoph; Bastkowski, Rene; Schäffter, Tobias; Prieto Vasquez, Claudia; Weiss, Kilian; Maintz, David; Giese, Daniel
• Is Part Of: Magnetic resonance in medicine. Volume 83:Issue 2(2020)
• Page Start: 635
• Page End: 644
• Publication Date: 2019-08-29
• Subjects: 4D flow -- k‐t SENSE -- nonrigid motion correction -- radial phase encoding; Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.27918
• Languages: English
• ISSNs: 0740-3194

Abstract

Abstract : Purpose: To minimize respiratory motion artifacts while achieving predictable scan times with 100% scan efficiency for thoracic 4D flow MRI. Methods: A 4D flow sequence with golden radial phase encoding (GRPE) was acquired in 9 healthy volunteers covering the heart, aorta, and venae cavae. Scan time was 15 min, and data were acquired without motion gating during acquisition. Data were retrospectively re‐binned into respiratory and cardiac phases based on respiratory self‐navigation and the electrocardiograph signals, respectively. Nonrigid respiratory motion fields were extracted and corrected for during the k‐t SENSE reconstruction. A respiratory‐motion corrected (GRPE‐MOCO) and a free‐breathing (GRPE‐UNCORR) 4D flow dataset was reconstructed using 100% of the acquired data. For comparison, a respiratory gated Cartesian 4D flow acquisition (CART‐REF) covering the aorta was acquired. Stroke volumes and peak flows were compared. Additionally, an internal flow validation based on mass conservation was performed on the GRPE‐MOCO and GRPE‐UNCORR. Statistically significant differences were analyzed using a paired Wilcoxon test. Results: Stroke volumes and peak flows in the aorta between GRPE‐MOCO and the CART‐REF showed a mean difference of −1.5 ± 10.3 mL ( P > 0.05) and 25.2 ± 55.9 mL/s ( P > 0.05), respectively. Peak flow in the GRPE‐UNCORR data was significantly different compared with CART‐REF ( P < 0.05). GRPE‐MOCO showed higher accuracy for internal consistency analysis than GRPE‐UNCORR. Conclusion: The proposed 4D flow sequence allows a straight‐forward planning by covering the entire thorax and ensures a predictable scan time independent of cardiac cycle variations and breathing patterns.