High-resolution 3D MR spectroscopic imaging of the prostate at 3 T with the MLEV-PRESS sequence

Magn Reson Imaging. 2006 Sep;24(7):825-32. doi: 10.1016/j.mri.2006.03.002. Epub 2006 May 2.

Abstract

A 3 T MLEV-point-resolved spectroscopy (PRESS) sequence employing optimized spectral-spatial and very selective outer-voxel suppression pulses was tested in 25 prostate cancer patients. At an echo time of 85 ms, the MLEV-PRESS sequence resulted in maximally upright inner resonances and minimal outer resonances of the citrate doublet of doublets. Magnetic resonance spectroscopic imaging (MRSI) exams performed at both 3 and 1.5 T for 10 patients demonstrated a 2.08+/-0.36-fold increase in signal-to-noise ratio (SNR) at 3 T as compared with 1.5 T for the center citrate resonances. This permitted the acquisition of MRSI data with a nominal spatial resolution of 0.16 cm3 at 3 T with similar SNR as the 0.34-cm3 data acquired at 1.5 T. Due to the twofold increase in spectral resolution at 3 T and the improved magnetic field homogeneity provided by susceptibility-matched endorectal coils, the choline resonance was better resolved from polyamine and creatine resonances as compared with 1.5 T spectra. In prostate cancer patients, the elevation of choline and the reduction of polyamines were more clearly observed at 3 T, as compared with 1.5 T MRSI. The increased SNR and corresponding spatial resolution obtainable at 3 T reduced partial volume effects and allowed improved detection of the presence and extent of abnormal metabolite levels in prostate cancer patients, as compared with 1.5 T MRSI.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Algorithms
  • Choline / metabolism
  • Citrates / metabolism
  • Humans
  • Image Processing, Computer-Assisted
  • Imaging, Three-Dimensional*
  • Magnetic Resonance Spectroscopy / methods*
  • Male
  • Middle Aged
  • Prostatic Neoplasms / metabolism*

Substances

  • Citrates
  • Choline