k-space weighted least-squares algorithm for accurate and fast motion extraction from magnetic resonance navigator echoes Academic Article uri icon


MeSH Major

  • Algorithms
  • Artifacts
  • Magnetic Resonance Imaging


  • Navigator echoes provide an effective method to monitor physiological motion, allowing motion artifacts to be suppressed by modifying the data acquisition accordingly. The displacement can be measured directly from the navigator phase using an algorithm suggested by Ahn and Cho (IEEE Trans Med Imaging 1987;MI-6:32-36). Although computationally efficient, it is susceptible to noise, particularly contributions from points at the edges of k-space. A k-space weighted least-squares (kLS) algorithm is proposed which fits a straight line to the motion-induced phase shift. The linear fit is weighted strongly to high SNR points near the k-space center and only weakly to the poor SNR points at the edges of k-space. This algorithm was found to be as efficient as Ahn's algorithm but more robust against noise.

publication date

  • November 12, 2001



  • Academic Article



  • eng

Digital Object Identifier (DOI)

  • 10.1002/mrm.1294

PubMed ID

  • 11675660

Additional Document Info

start page

  • 1037

end page

  • 40


  • 46


  • 5