EPI-BOLD fMRI of Human Motor Cortex at 1.5 T and 3.0 T: Sensitivity Dependence on Echo Time and Acquisition Bandwidth

Francesco Fera, Martin N. Yongbi, Peter Van Gelderen, Joseph A. Frank, Venkata S. Mattay, Jeff H. Duyn

Research output: Contribution to journalArticle

Abstract

Purpose: To investigate the sensitivity dependence of BOLD functional imaging on MRI acquisition parameters in motor stimulation experiments using a finger tapping paradigm. Materials and Methods: Gradient-echo echo-planar fMRI experiments were performed at 1.5 T and 3.0 T with varying acquisition echo time and bandwidth, and with a 4 mm isotropic voxel size. To analyze the BOLD sensitivity, the relative contributions of BOLD signal amplitude and thermal and physiologic noise sources were evaluated, and statistical t-scores were compared in the motor area. Results: At 1.5 T, the number of activated pixels and the average t-score showed a relatively broad optimum over a TE range of 60-160 msec. At 3.0 T, an optimum range was observed between TEs of 30-130 msec. Averaged over nine subjects, maxima in the number of pixels and t-score values were 59% and 18% higher at 3.0 T than at 1.5 T, respectively, an improvement that was lower than the observed 100% to 110% increase in signal-to-noise ratio at 3.0 T. Conclusion: The somewhat disappointing increase in t-scores at 3.0 T was attributed to the increased contribution of physiologic noise at the higher field strength under the given experimental conditions. At both field strengths, reducing the effective image acquisition bandwidth from 35 to 17 Hz per pixel did not affect or only marginally affect the BOLD sensitivity.

Original languageEnglish (US)
Pages (from-to)19-26
Number of pages8
JournalJournal of Magnetic Resonance Imaging
Volume19
Issue number1
DOIs
StatePublished - Jan 1 2004
Externally publishedYes

Keywords

  • BOLD
  • Brain
  • EPI
  • Optimization
  • fMRI

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Fingerprint Dive into the research topics of 'EPI-BOLD fMRI of Human Motor Cortex at 1.5 T and 3.0 T: Sensitivity Dependence on Echo Time and Acquisition Bandwidth'. Together they form a unique fingerprint.

  • Cite this