Encoding strategies for three-direction phase-contrast MR imaging of flow

J Magn Reson Imaging. Jul-Aug 1991;1(4):405-13. doi: 10.1002/jmri.1880010404.


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.

MeSH terms

  • Blood Flow Velocity
  • Blood Vessels / anatomy & histology*
  • Blood Vessels / physiology
  • Computer Simulation
  • Humans
  • Image Processing, Computer-Assisted / methods*
  • Magnetic Resonance Imaging / methods*