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Keywords:

  • fMRI;
  • k-t BLAST/k-t SENSE;
  • SENSE;
  • parallel imaging;
  • 3 Tesla;
  • fast spin echo

Abstract

Purpose:

To compare k-t BLAST (broad-use linear-acquisition speedup technique)/k-t SENSE (sensitivity encoding) with conventional SENSE applied to a simple fMRI paradigm.

Materials and Methods:

Blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) was performed at 3 T using a displaced ultra-fast low-angle refocused echo (UFLARE) pulse sequence with a visual stimulus in a block paradigm. Conventional SENSE and k-t BLAST/k-t SENSE data were acquired. Also, k-t BLAST/k-t SENSE was simulated at different undersampling factors from fully sampled data after removal of lines of k-space data. Analysis was performed using SPM5.

Results:

Sensitivity to the BOLD response in k-t BLAST/k-t SENSE was comparable with that of SENSE in images acquired at an undersampling factor of 2.3. Simulated k-t BLAST/k-t SENSE yielded reliable detection of activation-induced BOLD contrast at undersampling factors of 5 or less. Sensitivity increased significantly when training data were included in k-space before Fourier transformation (known as “plug-in”).

Conclusion:

k-t BLAST/k-t SENSE performs at least as well as conventional SENSE for BOLD fMRI at a modest undersampling factor. Results suggest that sufficient sensitivity to BOLD contrast may be achievable at higher undersampling factors with k-t BLAST/k-t SENSE than with conventional parallel imaging approaches, offering particular advantages at the highest magnetic field strengths. J. Magn. Reson. Imaging 2010;32:235–241. © 2010 Wiley-Liss, Inc.