title: Improved MR phase-contrast velocimetry using a novel nine-point balanced motion-encoding scheme with increased robustness to eddy current effects.
abstract: Phase-contrast MRI (PC-MRI) velocimetry is a noninvasive, high-resolution motion assessment tool. However, high motion sensitivity requires strong motion-encoding magnetic gradients, making phase-contrast-MRI prone to baseline shift artifacts due to the generation of eddy currents. In this study, we propose a novel nine-point balanced velocity-encoding strategy, designed to be more accurate in the presence of strong and rapidly changing gradients. The proposed method was validated using a rotating phantom, and its robustness and precision were explored and compared with established approaches through computer simulations and in vivo experiments. Computer simulations yielded a 39-57% improvement in velocity-noise ratio (corresponding to a 27-33% reduction in measurement error), depending on which method was used for comparison. Moreover, in vivo experiments confirmed this by demonstrating a 26-53% reduction in accumulated velocity error over the R-R interval. The nine-point balanced phase-contrast-MRI-encoding strategy is likely useful for settings where high spatial and temporal resolution and/or high motion sensitivity is required, such as in high-resolution rodent myocardial tissue phase mapping.
authors.affiliation: Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway. ekespe@medisin.uio.no
authors.forename: Emil K S
authors.initials: EK
authors.lastname: Espe
authors.forename: Jan Magnus
authors.initials: JM
authors.lastname: Aronsen
authors.forename: Biljana
authors.initials: B
authors.lastname: Skrbic
authors.forename: Vidar Magne
authors.initials: VM
authors.lastname: Skulberg
authors.forename: Jürgen E
authors.initials: JE
authors.lastname: Schneider
authors.forename: Ole M
authors.initials: OM
authors.lastname: Sejersted
authors.forename: Lili
authors.initials: L
authors.lastname: Zhang
authors.forename: Ivar
authors.initials: I
authors.lastname: Sjaastad
mesh_terms: D000818:Animals; D016477:Artifacts; D003198:Computer Simulation; D060526:Magnetic Fields; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D019047:Phantoms, Imaging; D012212:Rheology