title: Tracking of cyclic motion with phase-contrast cine MR velocity data.
abstract: A method of computing trajectories of objects by using velocity data, particularly as acquired with phase-contrast magnetic resonance (MR) imaging, is presented. Starting from a specified location at one time point, the method recursively estimates the trajectory. The effects of measurement noise and eddy current-induced velocity offsets are analyzed. When the motion is periodic, trajectories can be computed by integrating in both the forward and backward temporal directions, and a linear combination of these trajectories minimizes the effect of velocity offsets and maximizes the precision of the combined trajectory. For representative acquisition parameters and signal-to-noise ratios, the limitations due to measurement noise are acceptable. In a phantom with reciprocal rotation, the measured and true trajectories agreed to within 3.3%. Sample trajectory estimates of human myocardial regions are encouraging.
authors.affiliation: Department of Radiology, Stanford University, Richard M. Lucas Center for Magnetic Resonance Imaging and Spectroscopy, CA 94305-5488, USA.
authors.forename: N J
authors.initials: NJ
authors.lastname: Pelc
authors.forename: M
authors.initials: M
authors.lastname: Drangova
authors.forename: L R
authors.initials: LR
authors.lastname: Pelc
authors.forename: Y
authors.initials: Y
authors.lastname: Zhu
authors.forename: D C
authors.initials: DC
authors.lastname: Noll
authors.forename: B S
authors.initials: BS
authors.lastname: Bowman
authors.forename: R J
authors.initials: RJ
authors.lastname: Herfkens
mesh_terms: D006321:Heart / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008961:Models, Structural; D009038:Motion; D009200:Myocardial Contraction