Partial RF echo planar imaging with the FAISE method. I. Experimental and theoretical assessment of artifact

Magn Reson Med. 1992 Aug;26(2):328-41. doi: 10.1002/mrm.1910260212.


The fast acquisition interleaved spin-echo (FAISE) method is a partial RF echo-planar technique which utilizes a specific phase-encode reordering algorithm to manipulate image contrast (Melki et al., J. Magn. Reson. Imaging 1:319, 1991). The technique can generate "spin-echo" like images up to 16 times faster than conventional spin-echo methods. However, the presence of T2 decay throughout the variable k-space trajectories used to manipulate T2 contrast ensures the presence of image artifacts, especially along the phase-encode direction. In this work, we experimentally and theoretically examine the type and extent of artifacts associated with the FAISE technique. We demonstrate the existence of well-defined minima of phase-encode ghost noise for selected k-space trajectories, examine the extent of blurring and edge enhancement artifacts, demonstrate the influence of matrix size and number of echoes per train on phase-encode artifact, and show how proper choice of FAISE sequence parameters can lead to proton density brain images which are practically indistinguishable from conventional spin-echo proton density images. A comparison of contrast between FAISE and standard spin-echo methods is presented in a companion article referred to as II.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Algorithms
  • Artifacts*
  • Brain / anatomy & histology
  • Humans
  • Image Enhancement / methods*
  • Magnetic Resonance Imaging / instrumentation
  • Magnetic Resonance Imaging / methods*
  • Models, Structural
  • Models, Theoretical
  • Nickel
  • Time Factors


  • nickel chloride
  • Nickel