Encoding strategies for three-direction phase-contrast MR imaging of flow.
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.
Pelc
N J
NJ
Department of Diagnostic Radiology and Nuclear Medicine, Stanford University School of Medicine, CA 94305-5105.
Bernstein
M A
MA
Shimakawa
A
A
Glover
G H
GH
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*