Reduced phase encoding in spectroscopic imaging

Magn Reson Med. 1994 Jun;31(6):645-51. doi: 10.1002/mrm.1910310610.

Abstract

The effect of different spatial-encoding (k-space) sampling distributions are evaluated for magnetic resonance spectroscopic imaging (MRSI) using Fourier reconstruction. Previously, most MRSI studies have used square or cubic k-space functions, symmetrically distributed. These studies examine the conventional k-space distribution with spherical distribution, and 1/2 k-space acquisition, using computer simulation studies of the MRSI acquisition for three spatial dimensions and experimental results. Results compare the spatial response function, Gibbs ringing effects, and signal contamination for different spatial-encoding distribution functions. Results indicate that spherical encoding, in comparison with cubic encoding, results in a modest improvement of the response function with approximately equivalent spatial resolution for the same acquisition time. For spin-echo acquired data, reduced acquisition times can readily be obtained using 1/2 k-space methods, with a concomitant reduction in signal to noise ratio.

Publication types

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

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Artifacts
  • Aspartic Acid / analogs & derivatives
  • Aspartic Acid / metabolism
  • Brain / anatomy & histology
  • Brain / metabolism
  • Choline / metabolism
  • Computer Simulation
  • Creatine / metabolism
  • Fourier Analysis
  • Hydrogen
  • Image Enhancement / methods*
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging / methods*
  • Magnetic Resonance Spectroscopy / methods*
  • Models, Structural
  • Phosphates / metabolism
  • Phosphorus
  • Rats

Substances

  • Phosphates
  • Phosphorus
  • Aspartic Acid
  • Hydrogen
  • Adenosine Triphosphate
  • N-acetylaspartate
  • Creatine
  • Choline