Diffusion-weighted interleaved echo-planar imaging with a pair of orthogonal navigator echoes

Magn Reson Med. 1996 May;35(5):763-70. doi: 10.1002/mrm.1910350518.


This work describes a diffusion-weighted (DW) interleaved echo-planar imaging (IEPI) method for use on either conventional whole-body scanners or scanners equipped with high-speed gradient and receiver hardware. In combination with cardiac gating and motion correction with a pair of orthogonal navigator echoes, the presented method is time-efficient, compensates for patient motions, and is less sensitive to image distortions than single-shot methods. The motion-correction scheme consists of correction for constant and linear phase terms found from the orthogonal navigator echoes. The correction for the linear phase term in the phase-encode direction includes gridding the data to the Cartesian grid. The DW IEPI was used to image a phantom rotating about the slice-select direction, and motion correction was performed to eliminate ghost artifacts arising from motion in either the readout- or phase-encoding directions. DW IEPI with motion correction was performed on a normal volunteer and on a patient with a 26-day-old region of ischemia over much of the right hemisphere.

MeSH terms

  • Algorithms
  • Artifacts
  • Brain / anatomy & histology
  • Brain / pathology*
  • Brain Ischemia / diagnosis*
  • Echo-Planar Imaging / instrumentation
  • Echo-Planar Imaging / methods*
  • Humans
  • Image Processing, Computer-Assisted
  • Motion
  • Phantoms, Imaging