GRASE imaging at 3 Tesla with template interactive phase-encoding

Magn Reson Med. 1998 Jun;39(6):970-9. doi: 10.1002/mrm.1910390615.

Abstract

A new method for ordering the phase-encoding gradient is proposed, and an application for short effective TE gradient- and spin-echo (GRASE) imaging is demonstrated. The proposed method calculates the phase-encoding order from the signal decay of a template scan (hence "template interactive phase-encoding" or TIPE). Computer simulations are used to compare the point spread functions of different phase-encoding orders giving short effective echo times (kb centric GRASE, centric GRASE, centric TIPE). The conventional centric phase-encoding order is also considered for GRASE. The conventional centric method is sensitive to both amplitude and phase modulation of the signal in k-space. The centric TIPE method gives the least amplitude modulation artifacts but is vulnerable to phase artifacts. The TIPE experiment was implemented on a 3 Tesla system. To the best of our knowledge, we present the first in vivo GRASE images at this field strength.

MeSH terms

  • Artifacts
  • Biophysical Phenomena
  • Biophysics
  • Brain / anatomy & histology*
  • Computer Systems
  • Echo-Planar Imaging / instrumentation*
  • Humans
  • Image Enhancement / instrumentation*
  • Image Processing, Computer-Assisted / instrumentation*
  • Magnetic Resonance Imaging / instrumentation*
  • Phantoms, Imaging*
  • Reference Values
  • Sensitivity and Specificity