Predicting the macrovascular contribution to resting-state fMRI functional connectivity at 3 Tesla: A model-informed

Insights

Biophysical modeling can predict macrovascular contributions to resting-state fMRI functional connectivity near veins. This approach may help correct for macrovascular bias in fMRI studies.

Area of Science:

  • Neuroimaging
  • Biophysics
  • Vascular Biology

Background:

  • Macrovascular signals in BOLD fMRI pose challenges for detecting specific neural activity.
  • Large veins and arteries contribute significantly to resting-state BOLD signals, even in perivascular tissue.

Approach:

  • Developed and tested biophysical models (2D/3D cylinder, macrovascular anatomical networks) to predict resting-state BOLD fluctuation amplitude (RSFA) and functional connectivity (FC) at 3 Tesla.
  • Investigated the feasibility of modeling macrovascular BOLD FC and RSFA using anatomical data from angiograms.

Key Points:

  • Macrovascular anatomical networks enable feasible modeling of BOLD FC, outperforming simpler cylinder models.
  • Biophysical models accurately predict BOLD pairwise correlation near large veins (R² 0.53–0.93) but not arteries.
  • Modeling perivascular BOLD connectivity is feasible near veins (R² 0.08–0.57) but limited by distance and not effective for arteries.

Conclusions:

  • Biophysical modeling shows feasibility for simulating resting-state macrovascular BOLD signals and functional connectivity.
  • The methodology holds potential for correcting macrovascular bias in resting-state and task-based fMRI.
  • This work advances understanding of macrovascular influences on BOLD signals and offers a path toward improved fMRI accuracy.