Comparison of real-time water proton spectroscopy and echo-planar imaging sensitivity to the BOLD effect at 3 T and at 7 T

PLoS One. 2014 Mar 10;9(3):e91620. doi: 10.1371/journal.pone.0091620. eCollection 2014.

Abstract

Gradient-echo echo-planar imaging (GE EPI) is the most commonly used approach to assess localized blood oxygen level dependent (BOLD) signal changes in real-time. Alternatively, real-time spin-echo single-voxel spectroscopy (SE SVS) has recently been introduced for spatially specific BOLD neurofeedback at 3 T and at 7 T. However, currently it is not known how neurofeedback based on real-time SE SVS compares to real-time GE EPI-based. We therefore compared both methods at high (3 T) and at ultra-high (7 T) magnetic field strengths. We evaluated standard quality measures of both methods for signals originating from the motor cortex, the visual cortex, and for a neurofeedback condition. At 3 T, the data quality of the real-time SE SVS and GE EPI R2* estimates were comparable. At 7 T, the data quality of the real-time GE EPI acquisitions was superior compared to those of the real-time SE SVS. Despite the somehow lower data quality of real-time SE SVS compared to GE EPI at 7 T, SE SVS acquisitions might still be an interesting alternative. Real-time SE SVS allows for a direct and subject-specific T2* estimation and thus for a physiologically more plausible neurofeedback signal.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Computer Systems*
  • Echo-Planar Imaging*
  • Female
  • Humans
  • Male
  • Oxygen / blood*
  • Protons*
  • Signal Processing, Computer-Assisted
  • Signal-To-Noise Ratio
  • Spectrum Analysis / methods*
  • Water*

Substances

  • Protons
  • Water
  • Oxygen