Magnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine
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To develop a method for acquiring whole-heart 3D image-based navigators (iNAVs) with isotropic resolution for tracking and correction of localized motion in coronary magnetic resonance angiography (CMRA). ⋯ The ability to acquire isotropic-resolution 3D iNAVs every heartbeat during a CMRA scan was demonstrated. Such iNAVs enabled direct measurement of localized motion for nonrigid motion correction in free-breathing whole-heart CMRA. Magn Reson Med 77:1874-1883, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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To enable robust, high spatio-temporal-resolution three-dimensional Cartesian MRI using a scheme incorporating a novel variable density random k-space sampling trajectory allowing flexible and retrospective selection of the temporal footprint with compressed sensing (CS). ⋯ The complementary-Poisson-disc k-space sampling trajectory allowed a retrospective spatiotemporal resolution tradeoff using CS and view sharing, imparting robustness to motion and contrast enhancement. The technique was also validated using a novel approach of fully acquired variable-flip-angle acquisition. Magn Reson Med 77:1774-1785, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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To evaluate transverse relaxation (T2) and flip angle maps derived from signal pathway modeling of multiple spin echoes using simultaneous or independent T2 and flip angle fitting. ⋯ EPG fitting provides reasonably accurate T2, but is limited by poor accuracy in resulting flip angles, and T2 errors increase when flip angles are provided. Bloch simultaneous fitting of T2 and flip angle provides excellent results, but can be limited by multiple solutions which can be overcome by including a flip angle map. Magn Reson Med 77:2057-2065, 2017. © 2016 International Society for MagneticResonance in Medicine.
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Our objective was to demonstrate the feasibility of using hyperventilation as an efficient vasoconstrictive challenge and prior knowledge as denoising constraints for cerebral metabolic rate of oxygen (CMRO2 ) mapping based upon quantitative susceptibility mapping (QSM). ⋯ Hyperventilation is a feasible, reproducible, and efficient vasoconstrictive challenge for QSM-based quantitative CMRO2 mapping. Magn Reson Med 77:1762-1773, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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To develop a respiratory motion correction framework to accelerate free-breathing three-dimensional (3D) whole-heart coronary lumen and coronary vessel wall MRI. ⋯ The feasibility of a highly efficient motion correction framework for simultaneous whole-heart coronary lumen and vessel wall has been demonstrated. Magn Reson Med 77:1894-1908, 2017. © 2016 International Society for Magnetic Resonance in Medicine.