Rapid autocorrection using prescan navigator echoes

Magn Reson Med. 2000 Apr;43(4):583-8. doi: 10.1002/(sici)1522-2594(200004)43:4<583::aid-mrm13>3.0.co;2-b.

Abstract

Autocorrection is an adaptive motion correction algorithm that does not require an in vivo measurement of the motion record. A novel method for ensuring convergence of this algorithm when motion is severe is presented. A limited number of navigator echoes are acquired before the imaging sequence to obtain a "snapshot" of the object. Phase differences between the navigator and image k-space data are used as an estimate of motion-induced phase shifts in the image, followed by autocorrection. In phantom data a six-fold reduction in computation time compared to autocorrection alone was realized. These results indicate that this navigator/autocorrection combination may be useful for reducing motion artifacts and computation time for MR exams when motion along the image phase encoding axis is severe.

Publication types

  • Comparative Study

MeSH terms

  • Algorithms*
  • Artifacts
  • Automation
  • Humans
  • Image Enhancement / methods*
  • Magnetic Resonance Imaging / instrumentation*
  • Magnetic Resonance Imaging / methods
  • Models, Theoretical
  • Motion
  • Phantoms, Imaging
  • Sensitivity and Specificity
  • Wrist / pathology