Display Settings:

Format

Send to:

Choose Destination
We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Neuroimage. 2009 Oct 1;47(4):1381-93. doi: 10.1016/j.neuroimage.2009.04.048. Epub 2009 Apr 22.

Relationship between respiration, end-tidal CO2, and BOLD signals in resting-state fMRI.

Author information

  • 1Department of Electrical Engineering, Stanford University, Stanford, CA 94305-5488, USA. catie@stanford.edu

Abstract

A significant component of BOLD fMRI physiological noise is caused by variations in the depth and rate of respiration. It has previously been demonstrated that a breath-to-breath metric of respiratory variation (respiratory volume per time; RVT), computed from pneumatic belt measurements of chest expansion, has a strong linear relationship with resting-state BOLD signals across the brain. RVT is believed to capture breathing-induced changes in arterial CO(2), which is a cerebral vasodilator; indeed, separate studies have found that spontaneous fluctuations in end-tidal CO(2) (PETCO(2)) are correlated with BOLD signal time series. The present study quantifies the degree to which RVT and PETCO(2) measurements relate to one another and explain common aspects of the resting-state BOLD signal. It is found that RVT (particularly when convolved with a particular impulse response, the "respiration response function") is highly correlated with PETCO(2), and that both explain remarkably similar spatial and temporal BOLD signal variance across the brain. In addition, end-tidal O(2) is shown to be largely redundant with PETCO(2). Finally, the latency at which PETCO(2) and respiration belt measures are correlated with the time series of individual voxels is found to vary across the brain and may reveal properties of intrinsic vascular response delays.

PMID:
19393322
[PubMed - indexed for MEDLINE]
PMCID:
PMC2721281
Free PMC Article

Images from this publication.See all images (10)Free text

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Write to the Help Desk