title: Encoding strategies for three-direction phase-contrast MR imaging of flow.
abstract: Three encoding strategies for the measurement of flow velocities in arbitrary directions with phase-contrast magnetic resonance imaging are presented; their noise and dynamic range performance are compared by means of theoretical analysis and computer simulation. A six-point measurement strategy is shown to be quite inefficient in terms of velocity variance per unit time. A simple four-point method exhibits equal dynamic range; its noise depends on flow direction but on average is equal to that of the six-point method. An alternate, balanced four-point method has noise that is direction independent and has, depending on implementation, possibly lower noise levels. Either four-point method is more efficient and is preferred over the six-point approach.
authors.affiliation: Department of Diagnostic Radiology and Nuclear Medicine, Stanford University School of Medicine, CA 94305-5105.
authors.forename: N J
authors.initials: NJ
authors.lastname: Pelc
authors.forename: M A
authors.initials: MA
authors.lastname: Bernstein
authors.forename: A
authors.initials: A
authors.lastname: Shimakawa
authors.forename: G H
authors.initials: GH
authors.lastname: Glover
mesh_terms: D001783:Blood Flow Velocity; D001808:Blood Vessels / Q000033:anatomy & histology* / Q000502:physiology; D003198:Computer Simulation; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*