Meeting Banner
Abstract #1352

Biophysical simulations using realistic Vascular Anatomical Networks predict BOLD response attenuation at high stimulation frequencies

Grant Hartung1,2,3, Daniel E.P. Gomez2,3,4, J. Sébastien Proulx2,3, and Jonathan R. Polimeni2,3,5
1Computational Mechanics, Technical University of Darmstadt, Wetter, Germany, 2Radiology, Athinoula A. Martinos Center for Biomedical Engineering, MGH, Charlestown, MA, United States, 3Radiology, Harvard Medical School, Boston, MA, United States, 4Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 5Harvard-MIT Program in Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States

Synopsis

Keywords: fMRI Analysis, Blood vessels, Gray Matter, Flow, Blood vessels, Contrast Mechanisms

Motivation: BOLD response amplitudes decrease with faster stimulation frequency. The extent to which this is caused by hemodynamics is unclear.

Goal(s): To investigate the extent to which hemodynamics within the microvascular network impact BOLD response amplitude with increasing stimulus frequency.

Approach: Using realistic reconstructions of cortical microvasculature, we simulated hemodynamic responses to oscillating stimuli. We implemented arterial dynamics such that dilation propagated across the arterioles, with passive compliant ballooning of capillaries and veins.

Results: We found that transit time heterogeneity due to dilation propagation within the microvascular network impacted flow and oxygenation responses, resulting in attenuated BOLD responses with increasing stimulus frequency.

Impact: The role of vascular anatomy in BOLD responses attenuation at higher-frequency sensory stimulation is unclear. We apply biophysical modeling to investigate whether the cerebral cortical microvascular network influences BOLD dynamics and generates discrepancies between blood volume and oxygenation responses.

How to access this content:

For one year after publication, abstracts and videos are only open to registrants of this annual meeting. Registrants should use their existing login information. Non-registrant access can be purchased via the ISMRM E-Library.

After one year, current ISMRM & ISMRT members get free access to both the abstracts and videos. Non-members and non-registrants must purchase access via the ISMRM E-Library.

After two years, the meeting proceedings (abstracts) are opened to the public and require no login information. Videos remain behind password for access by members, registrants and E-Library customers.

Click here for more information on becoming a member.

Keywords