Ferumoxytol Enhanced Resting State fMRI and Relative Cerebral Blood Volume Mapping in Normal Human Brain

Neuroimage. 2013 Dec;83:200-9. doi: 10.1016/j.neuroimage.2013.06.066. Epub 2013 Jul 3.

Abstract

The brain demonstrates spontaneous low-frequency (<0.1 Hz) cerebral blood flow (CBF) fluctuations, measurable by resting state functional MRI (rs-fMRI). Ultra small superparamagnetic iron oxide particles have been shown to enhance task-based fMRI signals (cerebral blood volume fMRI or CBV-fMRI), compared to the BOLD effect, by a factor of ≈2.5 at 3 T in primates and humans. We evaluated the use of ferumoxytol for steady state, resting state FMRI (CBV-rs-fMRI) and relative cerebral blood volume (rCBV) mapping, at 3T, in healthy volunteers. All standard resting state networks (RSNs) were identified in all subjects. On average the RSN Z statistics (MELODIC independent components) and volumes of the visual and default mode (DMN) networks were comparable. rCBV values were averaged for the visual (Vis) and DMN networks and correlated with the corresponding DMN and visual network Z statistics. There was a negative correlation between the rCBV and the Z statistics for the DMN, for both BOLD and CBV-rs-fMRI contrast (R2=0.63, 0.76). A similar correlation was not found for the visual network. Short repetition time rs-fMRI data were Fourier transformed to evaluate the effect of ferumoxytol on cardiac and respiratory fluctuations in the brain rs-BOLD, CBV signals. Cardiac and respiratory fluctuations decreased to baseline within large vessels post ferumoxytol. Robust rs-fMRI and CBV mapping is possible in normal human brain.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Blood Volume / drug effects
  • Blood Volume / physiology*
  • Blood Volume Determination / methods*
  • Brain / drug effects
  • Brain / physiology*
  • Brain Mapping / methods*
  • Cerebrovascular Circulation / drug effects
  • Cerebrovascular Circulation / physiology*
  • Female
  • Ferrosoferric Oxide / administration & dosage*
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Male
  • Reference Values
  • Rest / physiology
  • Young Adult

Substances

  • Ferrosoferric Oxide