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The spatial and temporal characteristics of the apparent-diffusion-coefficient-dependent fMRI signal changes during visual stimulation.

Publication ,  Journal Article
Song, AW; Gangstead, SL
Published in: J Neural Eng
March 2004

The blood oxygenation level dependent (BOLD) contrast has been commonly used to detect fMRI signal. The majority of the BOLD signals are believed to arise from the venous and capillary networks. However, only those from the capillaries are spatially close to the neuronal activities, while the signals from large veins could be distant, rendering the overall localization inaccurate. In recent years, an alternative contrast using arterial spin labeled (ASL) perfusion imaging techniques has been proposed for predominant capillary sensitivity. Such acquisition methods, however, are intrinsically limited in temporal resolution and spatial coverage. Another contrast mechanism, free of such constraints, is based on the apparent diffusion coefficient (ADC) changes during brain activation using isotropic diffusion weighting. It has been shown that these changes are synchronized with brain activation and that they, as a whole, temporally precede BOLD activation, suggesting significant upstream arterial contribution. Moreover, the spatial overlaps between the upstream ADC and downstream BOLD activations are shown to be more localized in the capillaries, which are the temporal and spatial middle ground. In this paper, we sought to further investigate the temporal and spatial characteristics of ADC contrast with additional arterial signal suppression. Also, a pixel-based evaluation was performed in conjunction with the averaged global assessment. It was found that in addition to the known spatial discrepancy and global timing advance compared to the BOLD signal, the ADC activation endured significant temporal heterogeneities. Such fine spatial and temporal assessment could help characterize the exact signal sources of ADC contrast, and ultimately achieve exclusive capillary sensitivity.

Duke Scholars

Published In

J Neural Eng

DOI

ISSN

1741-2560

Publication Date

March 2004

Volume

1

Issue

1

Start / End Page

32 / 38

Location

England

Related Subject Headings

  • Sensitivity and Specificity
  • Reproducibility of Results
  • Photic Stimulation
  • Magnetic Resonance Imaging
  • Image Interpretation, Computer-Assisted
  • Image Enhancement
  • Humans
  • Evoked Potentials, Visual
  • Diffusion Magnetic Resonance Imaging
  • Brain Mapping
 

Citation

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Song, A. W., & Gangstead, S. L. (2004). The spatial and temporal characteristics of the apparent-diffusion-coefficient-dependent fMRI signal changes during visual stimulation. J Neural Eng, 1(1), 32–38. https://doi.org/10.1088/1741-2560/1/1/005
Song, Allen W., and Stacey L. Gangstead. “The spatial and temporal characteristics of the apparent-diffusion-coefficient-dependent fMRI signal changes during visual stimulation.J Neural Eng 1, no. 1 (March 2004): 32–38. https://doi.org/10.1088/1741-2560/1/1/005.
Song, Allen W., and Stacey L. Gangstead. “The spatial and temporal characteristics of the apparent-diffusion-coefficient-dependent fMRI signal changes during visual stimulation.J Neural Eng, vol. 1, no. 1, Mar. 2004, pp. 32–38. Pubmed, doi:10.1088/1741-2560/1/1/005.
Journal cover image

Published In

J Neural Eng

DOI

ISSN

1741-2560

Publication Date

March 2004

Volume

1

Issue

1

Start / End Page

32 / 38

Location

England

Related Subject Headings

  • Sensitivity and Specificity
  • Reproducibility of Results
  • Photic Stimulation
  • Magnetic Resonance Imaging
  • Image Interpretation, Computer-Assisted
  • Image Enhancement
  • Humans
  • Evoked Potentials, Visual
  • Diffusion Magnetic Resonance Imaging
  • Brain Mapping