Systemic Low-Frequency Oscillations in BOLD Signal Vary with Tissue Type


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Tong Y., Hocke L. M., Lindsey K. P., Erdogan S. B., Vitaliano G., Caine C. E., ...More

FRONTIERS IN NEUROSCIENCE, vol.10, 2016 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 10
  • Publication Date: 2016
  • Doi Number: 10.3389/fnins.2016.00313
  • Journal Name: FRONTIERS IN NEUROSCIENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED)
  • Keywords: BOLD, vascular density, amplitude of low-frequency fluctuation, low frequency oscillation, resting state fMRI, INFRARED SPECTROSCOPY NIRS, STATE FUNCTIONAL MRI, CEREBRAL-BLOOD-FLOW, RESTING-STATE, RESPONSE FUNCTION, CONCURRENT FMRI, HUMAN BRAIN, CORTEX, CONNECTIVITY, AMPLITUDE
  • Acibadem Mehmet Ali Aydinlar University Affiliated: No

Abstract

Blood-oxygen-level dependent (BOLD) signals are widely used in functional magnetic resonance imaging (fMRI) as a proxy measure of brain activation. However, because these signals are blood-related, they are also influenced by other physiological processes. This is especially true in resting state fMRI, during which no experimental stimulation occurs. Previous studies have found that the amplitude of resting state BOLD is closely related to regional vascular density. In this study, we investigated how some of the temporal fluctuations of the BOLD signal also possibly relate to regional vascular density. We began by identifying the blood-bound systemic low-frequency oscillation (sLFO). We then assessed the distribution of all voxels based on their correlations with this sLFO. We found that sLFO signals are widely present in resting state BOLD signals and that the proportion of these sLFOs in each voxel correlates with different tissue types, which vary significantly in underlying vascular density. These results deepen our understanding of the BOLD signal and suggest new imaging biomarkers based on fMRI data, such as amplitude of low-frequency fluctuation (ALFF) and sLFO, a combination of both, for assessing vascular density.